Well you have to make some animations to go with your Chiptune tracks..?
Have not tried it but it definitely looks like a highly interesting app for making pixel animations on a more professional level. The full version is in-app purchase and costs 
2.18 € / 3 $.
Wait I have an idea, has there ever been a full length pixel animated porno with the soundtrack being Chiptune? You now that you want to make it!
Wonder where the age limit on something like that would be?

Playstore link:
Pixel Studio - Animation maker

Here is an opportunity to get Reactable for half price until the 2nd of March...
Playstore link:
Reactable

Do not think that there is any other application that have this kind of high quality export of audio built in. It is open to discussion if you really ever going to hear or need more than 
24 / 16 bits  48 / 44.1 hz quality but one thing to point out is that it is nice to have the option and depending on if you are working with a studio or other people they may be used to work on these higher audio rates...
Update includes:
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- Audio Engine can now run on Sample Rates from 18kHz - 96kHz
- New High End Audio Export formats up to 32bit 96kHz (full version)
- New feature: Clone Master Params to complete pattern set
- BitCrusher Effect Max Sample Rate is now fixed at 44100Hz
- Fixed a rare crash bug when navigating between views on running sequencer (landscape mode)
Read the full release notes at http://www.planet-h.com/g-stomper-beat-studio/gst-whats-new/
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Playstore links:
G-Stomper Beat Studio 3
VA-Beast Synthesizer

The only drum machine with real time synthesis and with many parameters to manipulate directly is a must for anyone that wants a great sounding drum machine to use in a live setup to play with or record, go now and download this free and without publicity app if you have not already. Please when you open the app it is easy to dismiss it as something simple and I almost did the same when it first got downloaded but luckily I started to play with the parameters that there is some of for each drum and suddenly you have crazy manipulatable drum sounds at your disposition. For some people it is a turnoff that it does not have a save function but I do see that as an advantage as it is so good for direct recording / manipulation and it would kind of take away from it if you start to save presets and not use it as the living breathing sound machine that it is.
The update includes:
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• Improved 16 step sequencer
• Shuffle beat
• Two new channels
• New font and icons
• State is saved between sessions
• Removed annoying exit dialog
• Bug fixes
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Playstore link:
DMach

So JBlann is now taking a break from creating his own brand of sample / preset packs for Caustic and making some songs. Soon to publish some music on Playstore's own music page.
Well here is a taste of what will hopefully be the beginning of much music to come!

Playstore link to EIP Studios Sample packs:
https://play.google.com/store/apps/developer?id=EIPStudiosOhio

G-Stomper-3-ChipTune-Demo
Created with G-Stomper Beat Studio for Android 3.0 | www.planet-h.com
All Synthesizer sounds are created with the newly integrated VA-Beast Synthesizer using simple waveforms, arpeggiators and vibrato. The drums are from the 909 SoundSet, passed through a bit crusher effect.

For the adventurous that want to create hir own scales. Standard twelve tone or any kind of microtonal madness that your unhinged feverish brain can concoct!
With sound so you can listen to your home brewn scales.
Myself think that I will cowardly hide behind the standard twelve tones for awhile longer...
The application is for free.
Here is what the developer says about the application on his website:
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It’s a human tendency to assume that the things we grow up with are natural–just the way things are meant to be. Take music, for example. As Bill Gates famously observed, “Twelve tones ought to be enough for anybody.” Or maybe that was Mozart. Anyway, those of us in the West might think the equal tempered twelve-tone scale is natural (even though it took thousands of years and loads of adventures to arrive in its present form), but there are lots of people out there with a different opinion. Here’s a nice little app that lets you explore a musical space that might be completely new to you.
Microtonal eXplorer (MtX) allows you to create scales with any number of tones and any arrangement of intervals, then play riffs and chords from your new scale. Name your scale and save it in the database for later. Pull it out again whenever you feel like a little trip.
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Playstore link:
Microtonal eXplorer

Hey this is nice and effective. Made in Caustic 3 with one Beatbox and three Pad Synths.

Oh. This makes me happy and sad at the same time...
I am happy that this older application have gotten new life and seems to be developed further. My sadness stems from the fact that it had a much cooler name before making it a true underground app as it was not so easy to find before. Yes you had to scrape the bottom of Playstore search engine to find it and it was not clear that it was a music application at all.
It just had the simple name of SATAN and as logo a "hand drawn" upside down cross.
I downloaded it a long time ago under its old guise and there was no tutorials but after some mucking about it got learned but my device was too slow and SunVox got discovered and SATAN got forgotten...
Well it got some update, remember seeing that it got a Vocoder but it seemed like this open source app was going to be slowly languishing and finally disappear.
Now there is a reboot since some months and first the name got changed and the Logo so maybe there will be some more users now! 
It is a little bit like SunVox in that you can combine sound engines and effects in a modular fashion but it does use the more common piano roll sequencer instead of a tracker interface.
It is not as deep or flexible as SunVox but it does come with some nifty things one being able to play the sound engines on Tenori / Pad window being adjusted to whatever scale you chose. There is also the possibility to make your own envelopes for some parameters in the Sound engines. For sure there is some more things that I am missing but it is for free and can be just what rocks your boat! 
There is also a tutorial now and a less confusing interface so it is not so hard to figure out as before. The developer is selling himself short as he is not really giving a full description of his app not even mentioning what sound generators or effects are included.
But like said it is for free and without publicity or strange permissions so it is worth to take a look. I have it installed since some time and the idea being is to investigate a little bit deeper but having so much other apps to work with that I already feel comfortable with it will take some time and would love if anyone that is using it or in the future are using it would write me about your experience or music being made with the app and so it could be published here. - musicalandroid@yahoo.com
Would also love to speak to the developer but it is hard to find any contact email as there is none on the Playstore and the link to the Website just opens to a fixed screen...
So if you read this please write me.
In the end it is one of the more complete applications that you can find even though it seems slightly buggy but there is nothing this advanced for free...

Playstore link:
VuKNOB

JBlann has now finished his fourth installment of sample instruments and presets for the various synthesizers in Caustic 3. He says that now there will be a break from doing these and a focus of using them for his own music productions.
 So think that we will hear a lot of excellent music being made soon!
You do get a lot for almost no money in all of his sample / preset packs and also being construed in a way that they are very easy to use in combinations as the sounds are produced to be fully functional together.
There is not an embeddable video or sound sample of this pack except directly on the Playstore so if you are curious you will have to hear an example of this pack there.

Playstore link:
Caustic 3 Essentials Pack 4

Writing about the Moonsynth a couple of days before here is another example of it being used by the developer himself. It is the tablet in the lower left corner. 

Playstore link:
Moonsynth

So this year have heard so much professional music being made with Android music applications, some being released for film and here is one track that got released for a commercial video game. 
It must be just out of ignorance / laziness that there is people that deny the possibilities of Android and the music applications that exists... 

To read more about the game:
http://minotaurproject.co.uk/txk/

Here is a slightly mysterious one preset synthesizer. 
You can play it like the many theremin style applications thats out there this though being polyphonic and it contains something that I would like to see implemented more often at least in some more experimental synthesis apps and that is that the developer have built in some fluctuations and instability into the sound which makes it more organic.
I do wish that he expands on this idea but maybe giving more controls over the sound as like said before, as it is now it is just one basic sound. 
He have used the programming language Csound that is since some time possible using for Android applications it is also as the name suggests a programming language dedicated for developing applications / programs for sound. If this is interesting for you the developer of Moonsynth have written an article / tutorial how he went about making his two applications. The Source code is also available both for this one and his other application that is somewhat limited but nevertheless interesting specially for you noise hounds out there, that one being called Psycho flute.
He released Moonsynth about two months ago and was going to write earlier about it but felt that I wanted to record something using it and tried to fit it into a piece of music that it did not work for, luckily the Developer played this synthesizer as part of a live recording on a radio program so you can hear how it could be used. The radio show is also interesting for some of you as it does shows in a drone / experimental / noise stylelelee.
So he was in the second half of the program that is possible to listen to directly here but there is also a link to the radio show channel for anyone that would be interested in browsing and listening to the other shows as well.

Both Moon synth and Psycho Flute is for free and without publicity.

Links:

To the article that the developer Brian W Redfern wrote regarding Csound and Moonsynth:
Building a Touchpad Synth with Android and Csound

To the Radio Channel Dung Mummy Radio:
http://www.dungmummyradio.com/

Playstore links:
Moon Synth
Psycho Flute