Device : Galaxy S4 with kitkat.
After aprox. 10 minutes MCPE crashes and I get thrown out of MCPE.
When I restart MCPE and tries to start the world that crashed, MCPE shuts down. I have to create a brand new world to be able to play with MCPE again.
I can confirm this. I've got a Nexus 7 2013 running Android 4.4.3. This is the exact issue I'm having.