First of all, thanks for this great port of Civ on Android devices.
I am playing it on my Samsung Galaxy S2, and so far, I haven't noticed any bug. I really enjoy playing it, and there's only a couple of small things that could make playing much easier. Sorry if there is actually way-around for some of my suggestions and I didn't noticed them.
So, here are some suggestions:
1) Make enemy movements visible, or some alert when they come to my territory
(it happens to me that enemy unit kill my worker (or settler) just because I didn't see them approach (no alert). It doesn't have to be animated, or something... just quick jump on the screen where the enemy soldier is, or at least alert on the "information menu")
2) I would like separate screen for information (after the turns end), because if I have many "news", browsing becomes really hard, and I don't want to miss some useful information. Actually, I would certainly keep the actual bar, but I would add a separate screen to be used sometimes.
3) If it's possible, it would be nice to have research and trade treaty with AI
The third is not that important, and here's also some less important suggestions (I guess, you already have tons of that): automated worker, save game naming, animated movements, better UI for diplomacy (and also, more options for diplomacy), zoom in-out with two fingers... etc
Thanks again for reading, and I'll be back if I have some more suggestions.
Cheers to all.