A well known turn-based tactical war game Crimson Fields for Android.
This project is open-source and provided under GNU GPL v2 licence. Source code is available at: Github
Play against computer AI or your friends by e-mail.
Basic game controls: select unit, tap TWO! times on available hex to move, attack if possible, assign tasks to all of your units, press ‘Back’ key, select ‘End Turn’.
You can define keys in ‘Options’ > ‘Key Bindings’.