Hmm. Shouldn't be experiencing crashes then. I do occasionally but it's just because of bugs, nothing game breaking. I would suggest, of you're really desperate, uninstall (backing up mods and saves) and then reinstall and see if that helps at all.
Can you make a new pack (everything maxed out, draw distance very far and AA) fully compatible with iPhone 5, please? Is there possibility to change resolution to 1136x640? It would be really great if you could do something like that