This app was mentioned in 2 comments, with an average of 9.50 upvotes
Bitfinex released an Android App: https://play.google.com/store/apps/details?id=com.bitfinex.bfxapp
It has orderbook, live trades; you can trade (incl margin), transfer funds between wallets etc. Looks nice.
Edit: yeah, I somehow missed that it was already posted, sorry about that
Bitfinex just released their official Android app:
https://play.google.com/store/apps/details?id=com.bitfinex.bfxapp
Found in their changelog.