It is not so often lately that there is a new app and concept making an appearance. This looks like one. Have not tried it and am slightly skeptic as it seems more focused on the visual side of things but I could be wrong and it would have been good if they had a demo to try before as it is kind of expensive compared to other android apps.
But they do state that there will be a reduced free version soon.

Google Play:

Mazetools Soniface

EXPLORATION & EXPRESSION
With Mazetools: Soniface you can create various styles of electronic music. Everything based on common aspects of notation and music production. The in-app manual guides you towards a visual music experience.

HOW THE GRID WORKS?
The framework of action is a grid. Each line represents a single note. Shining lines are showing playing tones. 

X-Y CONTROLLERS & MULTI-TOUCH
Use multi-touch gestures for altering sound effects or explore the circular editing interface.

DYNAMIC SOUND MODULATION
Merge sounds and geometric shapes! Draw sound waves and automation curves freely with your finger to modify the sound effects.

GROOVE SEQUENCER
Just tap into the circle to set bass drum, snare and hi-hat steps. Easily adjust envelopes and pitch levels.

RHYTHMICAL MELODIES
Let the grid play a sequence of notes automatically using the arpeggiator interface.

LIVE MODE & SPECIAL VISUALS
Use different patterns to create song variations. Add a special kaleidoscope visual to a pattern as a highlight.

SAVE YOUR CREATIONS
You can store single Mazes, patterns or whole sessions into a set. Add one set into another and extend your playing time.

STAY CURIOUS!
We will bring spaced out updates and a reduced free version soon...

Get more information on:
https://www.mazetools.com/

Do you want to contact us? Visit our company website:
https://ectoplastic.com/WHAT'S NEW- Synthesizer based on an audiovisual grid implying common aspects of notation
- 3 way monophone drum synthesizer with envelope, pitch and noise level control and automation setup
- integrated manual
- unlimited pattern and instrument implementation
- arpeggiator interface, envelope setup & note step sequencer
- special “kaleidoscope” visual to highlight patterns
- full-screen mode
- easy composition playback
- versatile file library

Have been playing with this some days now and it is a cool thing.
It is dirty and different. It is not sample based and comes with a handfull of effects.
The layout is to scroll from the top to the bottom, starting with the bass drum and ending with the effects section.
There is not many drum machines for Android based on synthesized drums so that makes this interesting but what makes it even more interesting is that there is no drum machine that sounds like it either.

​Anyone interested in aggressive noisy sounds or chiptune should definitevely check this out.
Do think that it is also good to have anyway as it fun to tweak and just being different makes it an added possibility that is hard to get to with other apps.
There is a demo that is useful if you want to sit and record into a DAW for example the full version comes with preset saving and soon to come audio recording.

It is made using Pure Data and ported to Android using LibGDX which is the same as the developer working on Pure Data Party apps. It seems to be shortest way for someone that wants to make quality apps but do not have years to spend how to code properly...

The developer is also active musically and you can hear his music here:
https://soundcloud.com/thiiird

Google Play:

Dragon - Synth Drum Machine

Dragon is a drum machine built to quickly and easily make glitch, distorted, lofi drum beats and manipulate them live. The drums are simple and flexible, capable of some classic drum machine sounds and also new weirdness. Each is synthesized in real time and sent to a multi effect rig with variable speed stutter, bit reduction, pitched feedback delay and a resonant bandpass filter. The drums are triggered by a four pattern step sequencer. Patterns can be changed individually for each drum or triggered together for quick pattern switches for all drums.

Features:
Four pattern sequencer with local and global pattern control
BPM control with nudging
Save/load presets
Three drum synths:
-Bass
-Snare
-Hi-hat
Effects rig:
-Asymmetry and tanh(x) for tape like distortion
-Pitched feedback delay
-Retrigger (aka stutter/buffer) with variable speed and reversing
-Bit reduction
-Down-sample
-Reverb
-Resonant bandpass filter

Preset management requires permission for file storage read/write (optional on Android M+)

Unpaid version disables preset saving and audio recording

Audio recording coming soon. Possible future ports to desktop and ios. Made with Pure Data and libGDX

Full parameter and effect reference:

SYNTH PARAMETERS

Bass drum-
Freq: Frequency. Locks into semitones so you an harmonize easily
Decay: Amplitude decay
Freq Env Dec: Frequency envelope decay. Changes how fast the pitch drops
Freq Env Amt: Frequency envelope amount. Changes how much the pitch drops

Snare drum-
Tone Low Dec: Tone low decay
Tone High Dec: Tone high decay
Noise Dec: Noise decay
FM: Frequency modulate the low tone by the high tone
Freq: Frequency. Locks into semitones so you an harmonize easily, though overtones from fm and the high tone bring inharmonic tones
Freq Env: Frequency envelope. Changes how much the pitch drops
Delay: Feedback delay
Delay ms: Milliseconds of delay

Hi-Hat-
Freq: Frequency
FM: Frequency modulate the tone
Tone Dec: Tone decay
Tone Amp: Tone amplitude
Noise Dec: Noise decay
Noise Amp: Tone amplitude

EFFECTS

Retrig: Loop audio by the specified time interval (1/2, 1/8, 1/16, 1/32 notes)
Rev: reverse retrigger’s playback
Speed: control the speed of the retrigger’s playback

Bit Red: Bit reducer. Mixes in a low bit signal
BP Filt: Band-pass filter. All the way left is off
Tanh: Amplifies and the waveshapes the signal through a hyperbolic tangent curve. Creates a tape-like distortion
Asym: Adds to the signal, creating a DC offset. Doesn’t do much unless you have Tanh turned a bit
Down Samp: Down-sample the signal
Reverb: Mixes in reverb signal
Delay: Pitched feedback delay dry/wet
Delay ms: Milliseconds of delay
Freq: Adjust the pitch that the delayed signal is adjusted by. Also locks into semitones

Skarabee a long time user of Caustic have done some music software before but now he took the BeatBox machine from Caustic and made into a VSTi to be loaded up in a DAW.
It would be cool to one day be able to load the whole of Caustic as a plug-in and who knows?
Also his website is full of Caustic resources such as instrument presets skins, samples and suchlike.

Here is what he says and the link to get it:

https://sites.google.com/site/thecausticsessions/skara-plugins

Some users had a dream of a VST version for some Caustic's machines. So I followed this dream and made this extended version of the Beatbox as VSTi. 

Specifications:

•  12 slots
• 6 kits in the initial bundle.
• each slot can be routed to a separate audio channel (stereo)
• reverb included in the first stereo channel
• global pitch 
• Punch, decay, pan, and volume knobs
• Dynamic knob for the global response to velocity
• Multisampled for some kits (differents samples according to velocity)
• Note off message recognized (for embedded reverb samples length)

Kits details:

• Addicted: Taken from acoustic Addictive Drums V1. Multisampled
• Brushcat: one of my first Caustic kit now multisampled in stereo
• GSP rev: 80's style with included reverb (can be adjusted by the length of note) 
• Kaledokit: new one, electronic, modern and punchy (multisamples)
• KNA: another brand new inspired by an hardware machine (add 2 to each letter of his name to guess what)
• ODMX: the original Caustic kit revisited and boosted with tube preamp. some multisamples
• more kits to come...And I also can build a kit from your own samples, if you provide them

A new drum machine that with all the basice covered and some more good stuff like integrated sampler.

Google Play information:

https://play.google.com/store/apps/details?id=com.logicmutant.drummalogic&hl=en

Drummalogic SP is a minimalistic easy-to-use (programmable) drum machine/rhythm composer with unique loadable drum samples and some real-time audio effects (echo/delay, redux, flanger, etc.).

Create groovy drum loops and music using a unique library of cool drum samples and 2 by 8 sequencer grid. 

Features:

■ Studio quality sound
■ Drum samples from popular & classic drum machines (Roland TR 909, Roland TR 808, etc)
■ 16 drum pads
■ More than 6 (real-time) sound effects
■ Multi-touch
■ integrated sampler
■ Metronome, mixer & (2 x 8) sequencer
■ Live pad recorder
■ Pitch shifter/bend for each drum sample
■ Adjustable volume
■ 16 recording memories
■ BPM/tempo control
■ Wav export Performance or loops
■ 3 drum kit banks
■ Reverse drum samples
■ Real-time effect slider (for high-pass filter and low pass filter, for now)

This is the first application ready from a developer that is (soon?) releasing some apps that will work in tándem with Caustic. This one does not though but if looking for a competent sample based drum machine this could be the ticket.
​There is a demo versión to try...

Google Play:
​https://play.google.com/store/apps/details?id=com.teotigraphix.lildrummachine.demo

The Lil Drum Machine is aimed at users that want to experiment with rhythms in isolation and then have the ability to export their beats to wav, ogg, midi loops or a Caustic app multi-loop .pcmsymth preset.Create wav/mid loops for your favorite DAW, the Caustic App or just have fun creating your own unique rhythms.
MIDI is exported as one file containing individual channels for each Lil Drum Machine channel. Easily load in your favorite MIDI editor or DAW of your choice.
Contains NO ADS for demo and full version, just pure uninterrupted drum sequencing fun.
A Demo version of this application is also available on Google Play.
Main Features
- Create new projects from 12 existing kits.
- Load / Share existing projects.
- Export Selected pattern as wav, ogg or mid loops.
- Export all pattern loops to a Caustic App .pcmsynth Preset format. All loops are exported as wav files and mapped for loading into a Caustic PCMSynth as Caustic's native .pcmsynth preset format.
- Application settings for performance, UI scale and application defaults.
- Help link to online documentation, the app also installs local documentation in the Help directory.
- Master mix volume.
- Display for current project, pattern and pattern time.
- Play / Stop the pattern sequencer.
- Master and 12 channel VU metering.
- Tempo beats per minute 20bpm to 200bpm.
- Master effects editor, 2 insert effects and EQ on master channel.
Pattern/Sequencer
- Select pattern lengths of 1, 2, 4 and 8 measures.
- Select pattern custom color and name (custom pattern name used in loop and pcmsynth exports).
- Select pattern Swing, 1/8th and 16ths grid types.
- Select pattern Follow through each measure during play.
- Select between 16 unique patterns with varying measure length.
- Select current pattern view / edit position when not in pattern follow mode.
- Copy / Paste all channel content.
- Copy / Paste all selected channel content.
- Double selected pattern content.
- Clear All Channels pattern content.
- Clear Selected Channels pattern content.
- Sequence 16th notes in a classic step sequencer.
- Adjust each note velocity with sliders.
- Show / Hide Position, Pattern, Velocity and StepSequencer with right drawer toggle buttons.
Channel Features
- Load an external wav sample for each channel.
- Adjust Amp Level, Tune, Decay.
- Adjust Efx Pan, Delay, Reverb sends.
- Adjust EQ High, Mid Bass range frequencies.
- Adjust Filter to None, LowPass, BandPass, HighPass
- Adjust Filter Cutoff and Resonance.
- Add 2 Effect inserts per channel. Choose from Compressor, MultiFilter, Delay, Reverb, Distortion, Bitcrusher, Flanger, Static Flanger, Comb Filter, Chorus, Phaser, Auto Pan effects.
Drum Kits
- The Lil Drum Machine includes 12 classic and unique drum kits/percussion banks to get you started sequencing drum beats.
- All 144 wav samples are included so you can mix and match sounds if you do not have external wav samples already installed on your device. The samples are installed the Samples directory at application install time.
When exporting wav or ogg audio loops, the options exist to wrap the loop tail to beginning, cut the loop tail or detect full loop silence that contains all release effect tails. Exported audio exports to /root/LilDrumMachine/Exports on the device.

A easy to set up drum machine for practice or to make some beats fast but without sacrificing the possibilities of variation.

Google Play info:

Drum machine / pattern programmer:Create and play drum patterns / loops with a fast, easy to use interface. 3 levels per strike, 'choking' hi hat and fine control over tempo, swing and shuffle for great feel and timing.

Minimal ads and no time limits or interruptions. 2 built in kits with more available as upgrades.

No need to stop and start, even when loading a new pattern or a new drum kit. Patterns are saved as you go and you can create as many new patterns as you like.

Support for 2 bar patterns and the following time signatures: 
3/4, 4/4, 5/4, 7/8, 9/8, 12/8 (via 4/4 with 100% swing)

https://play.google.com/store/apps/details?id=com.atsiknobtg.drumr

The developer have done some apps for iOS and this is the first app for Android.
Did not play too much with it but it is pretty fun and it was not too complicated to figure out.
Without ads, for free and a it makes beats in a different way so worth checking out for anyone looking for something different.

Google Play info:

Insonic is a powerful music sound generator composing tool, designed for creating synth beats outside the usual beat box. Mixing between common BPM/Quantize and human move rhythms at live, this organic music sequencer has the ability to manipulate space rhythms and Q' time. Insonic's virtual sampler contains 144 sound sources; each sound spreads over 2 octaves and can be duplicated infinitely. Features: Wave recorder. Sound filters: HP/LP/BQ/EQ. Sound effects: Delay/Reverb/Flanger/Chorus Etc.

Not too exciting but for free and with more or less unobtrusive publicity...

Wrote about this before but if it got missed go and check it out as it is the only drum machine that synthesize the sounds real time and have X-Y pads for each parameter for 
each drum. Each drum coming with their specific set of controllers.
It is definitely something that is made for live tweaking or direct recording. 
Now it comes with the possibility to save presets which can be a good thing if you have tweaked the drums to perfection or for different starting points.
In my opinion it is one of the better apps for music making on Android specially for live tweaking and it is for free and without publicity.

Play Store link:
DMach

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....

This application that has been around for such a long time that it is possible that you forget about it if you tried it like say over a year ago.
Myself included have known about the app and used it but did not look into it for a long time until the other day when it got a update that includes the possibility to record an audio track outside of recording shorter samples for the pads. 
This is a good addition being easy to do and conforming to the directness of the rest of the application. I do like that to adjust for latency in the recording the solution is very simple.
Just drag the slider until the recording is in the right place. 
The recording works globally meaning that if the recording is done while just one loop goes in the background or if the recording is a fully sequenced song it will play or record the audio track as long as it is or as long as you are recording, independent of loop or song mode. 
But Electrum has also been slowly getting very nice additions over time that are very good.
So if you are looking for a no nonsense app to use as a sample player or drum machine where everything is clearly laid out making it very good for smaller screens and for live sets this could be something to look into again or for the first time. 
Another good thing is that it works on devices that are some years old by now.
In the Play Store it is listed as low as Android 1.6 this may be on the limit now with the 
audio track recording but there is a demo so it is easy to find out.
And like said before there have been a slow build up of features the last year or so making the app more flexible than can be thought at first.

Here is the Play Store list of features:
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● WAV file import - Load YOUR OWN SAMPLES from SDCARD. Long press a sound button to bring up the sample loading dialog. Also get more sound PAKS from Google Play, most are free, look for "Electrum Pak"

● Record VOCALS, freestyle rap along with the beat, or record an instrument (guitar, etc) - using the VOCAL/INSTRUMENT track feature!

● Use LOOPS as well as one shot samples

● Ringtone , WAV, MIDI, and Pad bounce export - load your song into FruityLoops or other DAW on your PC and keep working

● Load up to 16 samples.

● 16 Mute groups available, for more realistic drums

● Load MIDI drum files for quicker programming. Electrum comes with an assortment of pre-made MIDI files.

● Set samples or loops to retrigger on programmed slots or to play completely through before triggering the sample again

● Save your own custom drumkit settings

● RECORD samples to PADS with the microphone.

● Stretch loops to fit the current project BPM.

● Edit a sample's start and end point, pitch and pan Left/Right.

● Use other time signatures such as 3/4, 6/8, etc.

● Add some swing to your beats with the SHUFFLE setting.

● Add FX to your samples:

- Reverse
- Delay
- Distortion
- Reverb
- Stereo Spread

● Play Electrum with an external USB MIDI controller

USB MIDI Control has been tested on:

Galaxy Nexus phone
Galaxy Tablet 10.1
Motorola XOOM

● Plug a USB computer keyboard into your phone with an OTG USB cable and you can start/stop Electrum's pattern sequencer using space bar!

● Sharing - install the Soundcloud app from the market and you can share beats right to soundcloud (see Electrum's Menu->More->Share Exported)
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Playstore link:
Electrum Drum Machine