Stumbling across Kalimbas on Ebay the other day and seeing that it is possible to order nice tuned ones for not too much even some with output for amplification for cheap. There was temptation to get one but resisted if changing my mind this app looks like it could come in handy... 
It even have magic Kalimba mode!

Google Play:
https://play.google.com/store/apps/details?id=mbira.sansula.pianist.kalimba

Kalimba Connect recognizes notes music from Kalimba for easy practice with 650,000+ kalimba tabs from music songbooks.

This Kalimba tutor is one of the best virtual Kalimba for mobile & tablet. The app offers tons of songs with easy lessons, and we add new tabs every week! Don't waste more time, start playing now!...

★★★ Features: ★★★
- Full string Kalimba with 17 keys
- Play with 650,000+ song from music songbooks
- Connect with real Kalimba with notes recognition mode
- Daily Challenge mode
- Global Leaderboard
- Multi-touch and swipe supported
- Be able to record audio while playing
- Supports a wide variety of keyboard instruments (Piano, Grand Piano, Pipe Organ, Harpsichord, Accordion, Electric Guitar, Harp, Cello Pizzicato, Guzheng, Nylon Guitar, Plucked String, Music Box, Sitar, Xylophone, Harp, Vibes, Clarinet, Ukulele, Brass, Thai Bells, Tabbla, Dizi, Banjo, Flute, Saxophone, Cellto, Hamonica, Trumpet, Violin, Panpipe, Maracas, Tuba, Dulcimer, Kalimba,...)
- Lessons mode for easy learning
- Music games to practice
- Magic Kalimba mode added

With Kalimba Connect (Kalimba Extreme), you have a real virtual pro music instrument right in your pocket ! No need to carry your instrument all the time, you can start jamming at any time, play riffs tabs and chords anywhere, anytime.

The application is currently under development, and we look forward to receiving your feedback to the application become better..
For any questions, please visit our Fanpage: https://www.facebook.com/Kalimba-Connect-915396548655710/

This video is a documentary how they were in love and how he composed one of the great love tracks of the 21st century using the HumOn app...

The app is for free for the moment...
The basic idea being to transfer sound into standard notation.
Did try it a little bit just playing some piano music from Youtube and it seems that it is possible with some effort to get it to recognize some of the music.
Do not have the energy to spend time with it, but it is for free so why not try it?

Giggly Plistoure:
play.google.com/store/apps/details?id=fm.mystage.note_recognition

"Note Recognition & Audio Speed Changer - Convert Music into Sheet Music" is a note detection & audio speed changer app that converts music into an alternative sheet music. It helps you learning new songs by displaying sheet music suggestions for the recorded audio and provides you the functionality to change the audio speed and slow down your recorded music ("audio slow motion"). It's perfect for musicians who want to write down their own songs or who want to learn new songs and don't know how to play them.

The note analyzer works with pitch detection and frequency analysis (like FFT Fast Fourier Transformation for example) and is perfect for musicians (especially vocal and guitar or piano players). The note analyzer listens to your music, analyzes it's pitch and converts your music back into an alternative sheet music. You can use it to detect the notes of your songs (note identification, the app helps you creating a transcription), validate the pitch of your voice, sing into the microphone and use it as a vocal trainer or to transcribe your songs while playing along with your guitar (or whichever instrument you are playing). And of course, you can also use the note recognition app as a simple audio / voice recorder.

This note detector won't extract 100% of the played notes but depending on the quality of the signal the note detection algorithm will do a good job and will give you useful sheet music suggests. Because the detector can't separate multiple instruments you will get the best results if just one instrument is playing simultaneously or if you record your voice without any background music. Also, you should place your phone in front of your instrument, your voice or your speakers to improve the detection quality.

Please note that the note recognition algorithm performs intense mathematical calculations and it will take some time to analyze your recorded audio.



To be fair, here's what this app is NOT able to do:

Chord recognition
-----------------------------
This app has no specific chord recognition algorithm and therefore won't detect any chords! Don't play multiple notes simultaneously!

Separation of multiple instruments
-----------------------------
The note recognition can't separate multiple instruments. If you record multiple instruments playing simultaneously you will get bad detection results!

Live note recognition
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This app is not able to show you live note recognition results. Instead, it will take some time to perform the frequency analysis and show you the results.

Real sheet music
-----------------------------
This app is not able to show you real sheet music. Instead, it works with an alternative sheet music displayed at the screenshots.

100% match percentage
-----------------------------
This app won't detect 100% of the played notes and there will also be wrong detections. But depending on the quality of the input signal it will give you useful suggests!


The audio speed change functionality provides two music speed factors: 2x and 4x (as slow as normal). If you use this functionality, the note recognition app will zoom into the music score to make it easier for you. Mostly, it's recommended to change music speed if you want to analyze very fast songs because the sheet music gets illegible. Also, by changing the speed of your audio record you'll be able to identify very fast notes easy by ear.

Having bad note detection results sometimes? Try to open the settings and adjust the detail level at which it shall detect notes and convert music into notes.

The note detection was tested with guitar, piano and vocal but should work with every instrument as long as it plays notes above B1 (61,7 Hz) and convert music to sheet music.

Upcoming updates:

- A web app where you can upload your analyzed sheet music, edit it and convert it into MIDI.

HumBeatz are the same developers as a the DAW Amped Studio that is an online DAW that can be used Offline as well allowing for VST/i's.
​When writing about HumBeatz my thought was that it could have been a good idea to have an sequencer buillt in to expand on the two beats allowance but guess that this is a good idea as well and being able to use Amped Studio over the net allows for easy integration when having internet access.

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

To read more or try out the DAW (There is a free version and a subscription version for around five moneys a month):
​ampedstudio.com/

Have had fascination over the idea to create music from just vocals and have tried sometimes using Melodyne. For me it has not been easy as the things that come up using my head instead of an instrument or sequencer have been far less interesting.

In the end maybe having an instrument at hand to just pick out the notes is easier.
Having said that and maybe leaving the impression of negativity over such an app like this…
​I must say that I like it.

First on my mind was will it work, as there are other apps that have been trying their hands on note recognition but failed miserable. As anyone that tried these apps will tell you, that it is hard to use a garbled mess of random midi notes for anything.

Second was, will the app be used and not just occupying real estate on the phone/tablet?
Feel that yes there is definitively use for it. Maybe for me the first use is to quickly take out music that I am listening to without using an instrument and having the midi notes available for later.  Or use the bassline off a song as a starting point etc.

And yes it actually works! It does find the hummed notes with accuracy and there is some heavy algorithms going on behind the scene as it takes some times to transform the audio into midi, but it works.
There is also the problem of latency that they solved by letting the app listen to the metronome and audio recordings and get adjusted.
I mention these concerns as they are the most important to know if anyone is interested in getting the app.

​There is some setting up and trial and error but not too much and my biggest critique is that it only records two bars for each track but understandably it would be too heavy processing and waiting time otherwise. And for doing a bassline/melody/beat it works out fine.

Hopefully they maybe add a sequencer window that can be used for importing the midi and as such make longer tracks possible piece by piece.

Also feel that they should have a free version with maybe just one track and no saving or similar as even if it is not costing a fortune it is good to test it first just to know how well it performs on whatever device. But there is always possible to test it anyway and return it after an hour or two so it is not a big thing.

So it will be fun to see if I end up using this app or not but in either case I am happy that it is installed and having the possibilities that it offers.

P.s the sounds are General Midi but midi can be exported to use in other apps/programs.

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

HumBeatz is the revolutionary music making app that allows you 
to hum, whistle or beatbox and turn it into the musical instrument of 
your choice. Now you can quickly create musical parts and song sketches with just your voice!

HumBeatz is a four track loop recorder with two detection modes, Hum and Beatz. The detection mode translates your recordings to notes which are then played back by the included instruments or drum kits. You can also skip detection and use it as a simple loop recorder.

Hum detection allows you to quickly turn your whistling or humming into one of the over 30 virtual instrument included. Get your ideas out fast and easily anywhere!

Beatz detection translates your beatbox to any of the included drum 
kits! Using our machine learning algorithms you can also teach HumBeatz what types of sounds to use for your beatboxing.

Included with HumBeatz are a variety of drum kits and instruments, two effects (Reverb and Delay), a four-track Mix page and a Teach page.

HumBeatz is an excellent tool for any musician on the go and opens up music creation to everyone.