Progress not getting saved-MOJANG PLS READ

Now, dont get me wrong, I love Minecraft and would rate it 10 stars, but theres one problem that keeps annoying me. Whenever I play for a long period of time, my progress doesnt get saved. Ill do a bunch of cool stuff in my world and when I click the "quit and save" button, the app just crashes and I lose all my progress for about the last 10-15 minutes Ive been playing in that world. This is the first time this has happened in the 3-4 years I have been playing Minecraft PE. Mojang, please read this and try to fix the problem. ???

And a P.S. for people who keep on asking Mojang to add stuff from mods...IT WILL NOT HAPPEN!!!!! SO STOP ASKING!!!

?mcpe lover about Minecraft: Pocket Edition, v1.1.3