Your comments

I use Textastic on iPhone and iPad. I currently have to select all, copy, then paste into Notes app to sync to iCloud. Then copy out of Notes and paste back in on the other device.

If Textastic has auto-syncing to iCloud then I wonder how you would handle divergent branches? What if I made some changes on the iPhone after I made some other changes on the iPad? With Git this would become two branches. Like with Notes app it just makes two copies and there is no diff tool.

BTW, your forum software is buggy. I am on iPhone and right now, the text I am typing is obscured by the iOS keyboard (using Safari).