We have the same problem since the upgrade. We have an iPad 2 IOS 9.3.5. When you go into the app it comes up with the Mojang logo, then goes to a white screen and quits out. Tried rebooting and it didn't work. My kids don't want to delete and reinstall as they will lose all the worlds they've created.
Thank you, ours is working now. Upgraded from 1.13.0 straight to 1.13.2 on an iPad 2 (Model A1395) IOS 9.3.5. Played with WIFI on & off, haven't tested with VPN & parental controls, we don't have a Microsoft account, and have now stopped Automatic Updates. Thanks for fixing, but sorry to those who are still having issues.