Minecraft world keeps crashing after entering and going back to the home screen

I can load Minecraft and get to my worlds but once I'm in a world, after five minutes it will crash and bring me back to the home screen of my kindle. The app is still showing up as a tab but when i click it it reloads the app. I have uninstalled it multiple times and cleared the data too, but its not working. Please help i love mincraft very much, and miss playing.