GAME CRASH

When i downloaded the game everything went very well i played missions and everything but now since i dont know when when i open it it shows me the opening videos and then crashes jsut before the menu opens. I have gta 3 and SA and they never did that on my iphone 5 i did the update hoping it would work but it doesnt please help!

And i dont want to desinstall the game or i would loose my save.

Omg wtf bbq cookies about Grand Theft Auto: Vice City, v1.6