Like the idea of this but have not tried it... It also seems to have some kind of subscription type of thingy going on... but if looking to improve finger drumming this could be worth checking out?

Google Play:
​play.google.com/store/apps/details?id=com.paullipnyagov.rhythms

Rhythms is your ultimate music tutor that will help beat makers of all ages and levels to improve their beats techniques. Follow the rhythms of the music and learn at your own pace, whenever and wherever you want. 

WHO IS THIS FOR?
* Beat makers and finger drummers
* Complete beginners
* Advanced musicians

WHAT IS INCLUDED?
* Over 200 lessons with over 100 sound packs covering popular genres including EDM, Trap, Future Bass and so on.
* Guided playing: Rhythms help you play different parts of a track and then you can combine them together. The app will lead you to advance your skills and challenge yourself.
* Different modes: use tutorial mode to watch how to play the lesson. Use step-by-step mode to learn the rhythm. Use live mode to challenge yourself.
* Fun music game: addictive and fun gameplay tracks your progress. Practice every day to improve your results.
* Statistics: check your statistic and keep motivated to practice and learn.
* Portability: you can take Rhythms with you and play music anywhere.
* High sound quality: all sounds are made by us in our music studio or in collaboration with EDM producers.

RHYTHMS - the fun way to learn, play and master the pad controllers. Hit the notes at the right time to get the highest score! Practice every day and you’ll be amazed how fast your skills advance. 
Go and start playing now!

Great to have access to these rhythms with tempo adjustable tempo to boot and nice for any percussionist to learn something new.

Google Play:
play.google.com/store/apps/details?id=com.amvi.ikaatalarabiya

The easiest way to access, listen and learn the Iqa'at (Rhythms) of Arabic Music.

- Contains over 50 Iqa'a grouped in categories.
- Contains 5 Rhythms Categories including Sha'abi (Folk), Khaligi, Dabke, Taqsim and Muwashahat.
- Rhythms played on different percussion instruments of the Middle East, like Derbake, Riqq, Bandir and Tabl Baladi, depending on the specific rhythm.
- Each rhythm has auto loop on in order to practice the rhythm.
- Contains a Help page for the users who are not familiar with Staff notation or musical symbols

Note: - All the rhythms are showed and played in skeleton form, as the app goal is to learn the rhythms rather than playing rhythm with another instrument

Created by the 'Arabic Music Virtual Institute'. Visit our Youtube Channel to listen to Traditional & Classical Arabic Music and to learn more about Traditional Arabic Music

Remember learning the basic of drumming using drum notation and think that helped me so much with my musicality and am convinced that anyone making/composing music will have big push in the quality of their music learning some drums.
A lot of good music is just the rhythm that push it and melody harmony is not that important.
One very clear example is Bo Diddley and in more generic terms Reggae etc where the rhythm plays as much or more an important part of the music.

This app could be useful just for learning the basics just using feet, legs and arms/finger drumming  and/or study for programming better rhythms.
It does not have to be this app of course even though this one looks real good and will probably get it one day soon...

Gigolgliu Pleah:
https://play.google.com/store/apps/details?id=com.technimo.drumschool

Whether you're a beginner or a pro, Drum School is the perfect tool for advancing and expanding your skills. 
With a large selection of grooves, exercises and practice ideas, Drum School will continue to take you to the next level. 
It is also the perfect tool for easy access to a large library of professional sounding grooves for play along and as a reference library.
Included styles: Rock, Rock'n Roll, Alternative Rock, Heavy Metal, Punk, Blues, RnB, Hip Hop, Funk, Reggae, Ska, Disco, Drum'n Bass, House, Techno, Country, Bluegrass, Jazz, Swing, Dixieland, Ragtime, Fusion, New Orleans, Tango, Bossa Nova, Samba, Afro Cuban, Soukous, Calypso, Waltz and many more.

~ Featured in Modern Drummer and DownBeat Magazine ~

Drum School is divided in four main sections: Grooves, Practice, Technique and Favorites.

- GROOVES - 
This is the main section of Drum School with over 260 drum grooves in many different styles.
Each groove comes with:
- Standard drum notation with high quality graphics in portrait or landscape mode.
- High quality audio made from real drum samples that loop for play along practice.
- Variable tempo range of 30 to 300 bpm without any loss of audio quality. 
- Audio isolation of what each limb is playing, allowing the student to break down the groove into its basic components, learn them separately, and finally put them back together in various combinations.
- Bass lines that help learning and experiencing the relationship between the drums and the bass in each style in a fun way.
- High quality video performance by the author of the app, established and world renowned drummer, Ferenc Nemeth. 
- Multiple drum fills that can be practiced individually or in conjunction with the groove in 2, 4 or 8 bar phrases.
- Detailed description of performance details, learning tips and historical notes about each style.

- PRACTICE -
The practice section includes 133 drum exercises divided into: Basic Rudiments, Rolls, Flams, Drags and Hand Exercises.
Each exercise comes with:
- Standard drum notation with high quality graphics in portrait or landscape mode.
- High quality audio made from real drum samples that loop for play along practice.
- Variable tempo range of 30 to 300 bpm without any loss of audio quality. 
- Audio isolation of left and right hand.
- High quality video demonstration.
- Detailed descriptions of performance details and learning tips.

- TECHNIQUE -
This section includes 12 video demonstrations of basic drum technique for hands and feet.
Each video is accompanied by a detailed description and learning tips.

- FAVORITES - 
This is where you collect your favorite grooves and the ones you are currently working on.

Visit the support website for a video demonstration.

Looking for some rhythms that you may not be accostumed to?
Nice app this as the free version comes with a bunch of rhythms that can be adjusted in tempo, tonality and fills. The Paid version comes with a sequencer to roll your own using the percussion sounds.
It is great that it is possible to get a free adjustable rhythm library that they could have charged for and for a little money extra expand on it.

Google Play:
https://play.google.com/store/apps/details?id=com.rajaramaniyer.jalra

Meet, Jalra - Carnatic Mridangam, an app to make your android device to play mridangam for Indian classical music, dance or bhajans.

This app is musician's best friend. Every student and professional will need it. The purpose of the app is to accompany the musician with the sound of Indian percussion instruments called Jalra and Mridangam. Once you spend few days with this app, figuring out how to configure and use it, the app will become the best solution for music or dance practice and performances. You can also use it for Bhajans.

The app is very simple to use. It has many advanced features like playlist and beat editor. The design is very intuitive and needs no training to use it.

If you are a student, show this app to your teacher, who should be able to tell you how to use it properly for your practice. It will help you get a hold on the rhythm of your music. If you are a teacher, teach the app to your students, for helping them to improve their rhythmic skills.

Detailed Help
A very detailed help is available at this link: https://jalraapp.wordpress.com

Features

-> Mridangam and Tambura all pitch
-> All Talam/Tala supported (count of 3, 4, 5, 6, 7 and 8)
-> Carnatic Music's Saptha (7) Alankara Talams are avaialble
-> Displays count for visual feel of the rhythm
-> Set any tempo you like for the beats
-> TAP twice to guess/judge the tempo
-> No need to keep screen on while playing, runs in the background. Option to keep the screen on if you wish.
-> Convenient notification to stop/start and to bring the app to front. Works even from Android Wear (Watch)
-> Create Playlist - **NEW** paid feature, combine more than 1 style to create a new longer loop
-> Create and Tweak Beats in the Beat Editor - **NEW** paid feature
-> Save local files to google drive as backup or sync across multiple personal devices - **NEW** paid feature
-> Keep Screen On, if required

Fill Button

While the app is playing a style, hit the Fill button to play a static fill variation once. 

End Button

When playing any variation, hit the End button to wait for the app to finish the active playing the active sound and then stop. 

Show / Hide Playlist

You can show or hide the playlist with a toggle button. With the playlist hidden you will get the classic screen simple screen to configure the app.

Beat Editor – InApp Purchase

Press and Hold any one style to open its beat editor. Every beat is divided into 4 parts, with a on/off button for each part. Touch them to swith each part on or off to tweak the beat. When you try to use it for the first time, a prompt will be shown to buy the feature. Once you have bought the feature, you can design / tweak the sound on the beat editor.

Play List

You can add a style into the playlist. When you add a style into playlist, the tempo and count that is active will be used for that item.

There is option to Save playlist to save them as local file. They are internal to the Jalra app. These files will not be visible in File Explorer app. Careful, these files will get deleted when you uninstall the app!

Sync files to Google Drive – Paid Feature

Playlist and new Styles are stored in app's internal files. These files will get lost if you uninstall or reset phone. So there is a feature available to sync app's files with google drive account as backup. Even on google drive these files will be hidden. However, you can see their existence under Settings -> Managing Apps -> JalraApp.

Hide Ads – Paid Feature

The app shows banner ads. If you want to hide it, you can buy NoAds feature by click on "Show or Hide Ads" menu option.

Do not know how well this works and the app is still in Beta but it if it works good this mighty cool.
To read more about the controllers:
https://www.freedrum.rocks/

To read about how to hook it up with G-Stomper app:4
https://www.freedrum.rocks/setup/frequently-asked-questions/playing-with-android-gstomper
​

So this video show pretty clearly that there is Android devices that can work with totally acceptable low latency. They are using G-Stomper that admittedly are optimized for low latency as well. The Freedrum sticks looks like a great thing to have as well as a drummer. The sticks are still on Kickstarter but fully funded.
To read more regarding the Sticks go here:
https://www.kickstarter.com/projects/freedrum/freedrum-the-drumkit-that-fits-in-your-pocket/

So the last update brought with it the possibility to buy midi instruments directly from the app as soundfonts. So here is some demo sounds of drum kits...

Came in the beginning of June and has compound times that seems to be something that a lot of people desire.

Play Store Description:

An easy to use sample-based drum loop/beat maker.- single tap note entry/delete
- note velocity editing
- easy copy/paste to assemble blocks/long loops, or even complete song structures
- combine simple and compound time signatures on a per bar basis
- quantize individual drum kit parts for complex rhythmic patterns on a per beat basis
- mixer for level balancing and pan settings
- pads to play samples live
- ADSR editing for drum samples
- import own samples (mono, 16-bit, 44.1kHz, WAV)
- bass editor 
- export as a CD quality wav file (16-bit, 44.1kHz) for direct import into DAW software.

Fun and easy beat creation!

Version 1.0.4 comes with one set of drum kit samples and one set of bass samples.

Planned features(already under development) include filters, additional samples sets and additional tracks for synths/keyboards/strings etc

System Requirements:
Should run on any android version from Gingerbread onwards although performance on older devices is likely to be sluggish. As with all software, best performance will be on newer devices with fast/multiple CPUs and graphics processors.

It is many of these types of apps out there but the developer has worked on getting this to be as low latency as possible and to my ears it is very responsive and totally usable for live recording and in difference to 90 % of these types of apps there is no publicity.
The samples are fixed but for sure there is some of the sounds that can be used like laying a hi hat pattern down and get some real time played groove recorded!
For freeeeeeeeeeeeeeeeeeeeeeeeeeeeee...

Play Store link:
Heartbeat Drum Pads

It is very easy to use and what it does is randomizing a beat for you and you can see the rhythm laid out in notation. This you can change around with accents and changing the drums around plus more settings to adjust things to your liking.
This is excellent if you have a hard time programming drums as you can just copy the rhythm patterns in your sequencer when there is something that sounds good. 
As a bonus learning how to program rhythms just by copying the patterns would get fixed in your minds eye for future use.
Not to talk about using it for practicing instruments or to learn drums, hey there is even hand / foot and accent notation.
But there is one glaring omission and that is that it can only play one drum sound at a time...
So for the hi-hat patterns it is still necessary to think a little bit for yourself, the same with the kick and snare... and there is no time signatures except 4/4.
There is bpm though and it can still be of help as it can make the ground work easier for non players.  Hopefully it will be expanded upon as for me it could be a lot of help rhythmically.
For free and it is supposed to be publicity but there has been none on my device.

Play Store link:
Linear Grooves

It is meant mostly for having rhythms to practice to, but it also contains a sequencer that you can program. 
The Sequencer contain a fine degree of steps (one quarter note contains 24 micro steps) to get very intricate rhythms going making it less good for direct programming but very good for the discerning musician that needs the rhythms just right. 
The sequencer is not the main course though as the app is more for having rhythms already made with variations to switch things up with during practice sessions. 
Yes there is a bunch of these apps out there but this one comes with three things to make it stick out from the crowd. 
First being is that the samples comes round robin (playing slightly different versions of the samples at each hit) This as far as I know does not exist for any sampler at all for Android.
The second thing is something that I wish was a function built into more apps and that is a humanize function so you can decide how erratic the hits will be as no human can play in perfect beat this in combination with round robin adds to humanize the rhythm if you want.
The third is that you can use a footswitch with a USB-OTG cable to switch in between fills, intro etc while playing a instrument.

It comes in three flavors all of them containing all the functions but having a varying degree of drum sets / sounds and rhythms already programmed.
The most basic one is for free which is a good thing especially if you are thinking to use it for programming rhythms as the programming of rhythms can be slightly tedious (it is not that bad but there is a lot of people that have no patience). One thing that could be good to implement would be to have the "micro" (ticks) steps in between collapsible that you have in SunVox and in other trackers making it easy to program the main rhythm and then add smaller additions. Otherwise if there is only a need to have rhythms to practice to there is not anything negative to say about the application.
Maybe it would be good if you could import midi files. 
Actually it could be hard to work into the same app as it is set up but maybe... I am not a programmer and have learnt what seems to be obvious and simple to a non programmer...
is often not the case.

But definitely worth checking out if you need a drummer / rhythms for your practice sessions in either case.

So to check out what the different versions have to offer:
Drum Machine Drummer Friend Free
Drummer Friend - Drum Machine
Drummer Friend HD Drum Machine

In the first video he is switching the rhythm by hand this is not necessary if you have a foot switch. Which is one of the selling points of the app. But I think the video is before this was implemented.
In the second video he has hooked up a audio receiver to his computer that records the audio through Bluetooth. I did not know that this was possible until the developer told me and that this is possible for almost any (or all) Android devices...
Learning some basic facts about Android every day....

Normally these type of applications do not get written about too often but as there was some investigation into a new application called Recording Studio ( that has some good sampled instruments but at this moment with shaky timing and other chuppililupps ) stumbled across this one which is an expanded version of an application called Perfect Piano and has been around since the dawn of Android music applications. 
It has now matured into something more and can be useful for sketching out ideas for real instruments. It comes with a lot of instruments and there is many more that you can download to incorporate into it for free. 
It is made for direct recording and feels responsive enough to pull it off depending on device and it is USB compatible for devices that can use OTG cable. Remember to that if the latency are too high for your device you can do the recording in slow tempo and then speed it up. Strangely enough it has a sequencer but only for the Drum machine but think as that would be the part that is most important for recording the rest it is all good. Coming with Midi export you can also adjust timing etc in another application / program that can open Midi.
It is also meant for being able to practise the piano and it can be notes falling or scrolling notes.
It does comes with publicity which is normally annoying but they have made it non obtrusive and it is not annoying and if you do find it disturbing there is always the possibility to turn off the internet connection for a while? 
Another reason that I am writing about this application is that there is a contest going on that will be written about in the next post!
Playstore link:
Walk Band

Here is a short but to the point how to make percussion sounds using subtractive synthesis.
The intersting part that it is made using a high end Moog synthesizer and it would be funky if you dear readers tried out any of your Android synthesizers using the same instructions and see how close you can get. If you are happy with your result please share with us.
You can send your result and presets etc here - musicalandroid@yahoo.com

It is strange that nobody has tried to do a drum machine yet with real time synthesis.
Here is one in either case that has been out for about a month.
Not only is it the only one it sounds good to. 
This is the second application that have been discovered by me the last month that almost got dismissed as soon as it got opened. As there is so many crappy pad / sequencer chuppililupps out there it looked like all it was going for it came down to four sample based drums in a very short sequencer. 
Maybe it was that the look was different or that it was no publicity but lingered a little bit longer on it than would have happened otherwise. Discovering that pushing the left side a new page opened up where you got access to different parameters for each drum making it a truly flexible gem of an application.
In the simple interface is hidden a world of synthesized drums and even though it is only one bar to the sequencer it is so easy to switch the pattern around in real time. 
Switching page you then have a very good way of interacting with the touch screen making changes again in real time. This has to be downloaded by anyone of you that want to use a good drum machine for live tweaking. Here it is would I dare say even better for live work than many hardware drum machines as you can sweep sounds with your fingers.
In this application it feels like a save mode is unnecessary as it is so good and easy to set up 
and so fun to play with that it helps that you do not get bogged down in presets or saved sequences.
Plus as said before it sounds excellent!
I am just happy that it did not get thrown out, dismissed and cast out of my life because of short attention span!
Bonus points is that it is for free (would gladly have paid for it) open source so you can download the code and even better made in Pure Data, the open source visual programming language for making music.

Playstore link:
https://play.google.com/store/apps/details?id=net.simno.dmach
To get the code for Pure Data go here:
https://github.com/simonnorberg/dmach

Well at least I tried it...
Just posting because the video is funny and even if it is not good or much of use,
any application that tries to take us out of the complacency of doing things as always deserves some kind of attention...
There is another application that is similar that if for some reason this excites you called Air Drum+

Playstore links:
Air Drums Thump N Snap
Air Drum+