Have you looked at anything outside the tilesset overhead? It sounds like that's going to dominate (quick check, run with and without tiles and compare), but there may be some significant bits in the main game code as well.
No, I haven't looked in detail at other areas of the game yet. Every user I've spoken with who had troubles running tiles on Android (usually due to a low-spec device with < 1GB memory) was able to run the game fine in ASCII mode, so I agree that tiles are most likely the biggest culprit, but I haven't verified that. (And if we apply Programmer's Law, the one thing we haven't verified which we're certain is correct has a 99% chance of being incorrect, hehe.)
Also for anyone looking to contribute, the source code + release APKs is now permanently available on GitHub: https://github.com/a1studmuffin/Cataclysm-DDA-Android
sidav: Thanks for the report, I'll see what can be done.
Taerzik: Yeah absolutely smaller tilesets will reduce memory overhead. As you say some people have had success with Hoder's tileset, though it will depend on your device and available memory. Glad you got it working :)
RipRoarinBoogerPenis: Does the same issue persist if you don't delete the unused tilesets? I know Cata will try and revert to a few default tilesets if it can't find the user-chosen tileset, perhaps that's tripping it up. Awesome username btw.
Kirikman: v0.30 (latest) is using 0.C-20819-gc7f9eb7. You can now see the Cataclysm DDA version in use via the GitHub releases page: https://github.com/a1studmuffin/Cataclysm-DDA-Android/releases
Thanks for the feedback about resetting shortcuts too, duly noted.
hatcher: I will do a new experimental update soon. It does take a bit of time to do the update though as I have to merge it with my UI changes, and I've had some unexpected commitments lately hence the delay so far. I won't be doing them very frequently regardless - I'll aim for once every month or so, unless someone else is dying to help out and loves 3-way merging code! :) I'll also update when a major version is ticked.
zer0pol: Santa delivered the goods! Hahaha. Thanks for the kind words and bug report, I'll see if I can repro this locally.