I'm glad you're enjoying it, and I hope you continue to enjoy what I have planned for the future!
The war map is just a basic imagemap so there's no reason in the world why there should be any slowdown. Perhaps try restarting your device (full power off and power down) or freeing up some storage space (or both) as it sounds like your phone is seizing up while it tries to shuffle memory around.
Sorry I can't be more help