Minecraft does not start. Right after Mojang loading it disappears on ipad2

Ipad2 using iOS 9.3.5 version and when I open minegraft it loads the Mojang logo then goes blank with white screen and the off . Over a month now. I bought mine craft twice, also for my android phone and I faced the same problem for a while, then one day it just opened again. What can I do please?