1. Nitpicking: When thumbs-upping/someone, it's possible to repeatedly tap the thumb and drive it as high or as low as you want. Server appropriately restricts the amount of times you can do it, but the client side will let you do it to your hearts content. I'm guessing that isn't the intended behavior.
2. The text editor has a frustratingly annoying feature on Android. In the event I typo something, I like to long press the word (to select it) and then retype. Long pressing (as it stands) selects the word, but it pops up a context menu (copy, cut, paste) and minimizes the keyboard, effectively killing my ability to retype over the selected word.