I'm not sure how easy it is to get at the program files on iOS. Isn't that stuff filtered by the default file browser? I think I saw reference to an app that can do a bit more without any need to modify the OS, but this is all too far out of my experience base to offer any practical solution. How does the process work on Android? Aren't the data files stored in a compressed file of some sort?
yeah, you have a big file (and in sa 2) which is always called for big apps (appname).obb (in the case of vice city com.rockstargames.gtavc.obb)
you just rename .obb to .zip and extract main.scm from the data folder
I've extracted .obb files before, but I've never tried modifying the contents of an .obb file. Can you just re-zip the file and change the extension back to .obb for the modifications to commit? Or can you do what Orion suggested above and place the modified file in a particular folder?