I haven't taken any hard data, but keeping memory clear of background programs seems to help. Unfortunately, these pop up *during* play. Best thing I've found is Advanced Task Manager (free) on Android, set to Regular Kills (every 1 minute is the most frequent it will do). It seems to make a difference between the game quitting every 30-90 seconds (without the Task Killer on), versus quitting every 2-4 minutes (with it on).
Or maybe I'm just imagining things. Either way, it's not worth my playing right now, so I'm saving up for a new phone. I get on once in a while using an old (slow and laggy) (and tiny screen) HTC phone, but it hurts my eyes, and the lagginess is a real pain.
Manfred