If you do not use pure data maybe this is the excuse you need to start learning it as with this app you can make patches on the go or just take advantage of patches that has been made already by others.
It is "restricted" to Pure Data Vanilla meaning that extensions to Pure Data made by users are not allowed but it is hardly restrictive as almost anything that can be thought of as a music app is covered.
Really recommend for people to check out Pure Data and see if it is not worth the effort as it is for free and very deep if you want it to be. In a sense this and MobMuPlat is maybe the most advanced music apps available for Android! As even without any skill in doing patches there is so much made already.
Have not learned it in any kind of depth but was studying some this summer and even though it is not a stroll in the park it is not very hard either if you get into the concept ( talking as a non programmer ) and it has the added bonus of actually learning the basics of other programming languages as the principles are the same except that Pure Data is exclusively made for musical
( and some graphic ) intentions and is easier to use for people that are more visually inclined as it is not writing code but the code is in the form of boxes interconnected so you can see the relationship between the different programming commands which can be hard with written code...
It is for free and works as is visible in the picture below- All the different commands are on the right side and it is just to drag them out and place them and make your patches.
So now there is two excellent apps for Pure Data usage!
MobMuPLat that allows already made patches to be turned into Android apps with an interface and this one where you can make the patches on the go, or load patches and use without a nice GUI but this can be loaded into the free desktop part of MobMuPlat and then add a fancier GUI?
In either case it is amazing that this possibility exists!
There is a lot of tutorials and books etc how to use Pure Data that is available through the Pure Data website or Youtube etc.
Playstore link:
https://play.google.com/store/apps/details?id=org.mpd
Pure Data website:
http://puredata.info/