Minecraft pocket edition does not start anymore on IPod touch

Since last update of Minecraft pocket edition on my IPod touch (v 0.11.1) in early June, The game does not start anymore. The white screen with Mojang logo come up for 20 seconds and then, the game closes. The IOS version off my IPod is 6.1.6 and there is plenty of available memory. The game was working perfectly before last update.