Really trying not to weigh in here, but I've done exactly this on both iOS and Android, and it IS hard.
iOS has three resolutions to worry about. Android dozens. That means a lot of testing, and complex layouts are a pain. Tables, easy. Map views, easy. Auto-scaling layouts with a couple dozen or so elements all relative to each other, hell.
Upgrading on iOS is very very fast. iOS6 is released (all recent devices, same day) and within weeks >50% in the field have updated. I've never seen an adoption rate like that in all my years in this industry. Phenomenal. When we released OVMS for iOS, it required iOS5 (which had only been out for a few months at the time) - we got 2 people tell us that was an issue for them. 2. Both upgraded.
Devices on Android don't typically update past one major version, and even then it takes many months before it is available. When we first beta tested OVMS for Android, it required 2.3 (because that included encryption libraries missing in 2.2), but more than half the users were still on 2.1 and 2.2 (even though 4.0.1 was already shipping on new devices). It was a real pain, and we had to bring in a bunch of encryption libraries to get 2.2 support.
I'm not saying Android is bad, far from it. Just that the fragmentation and update delays make it much harder to get broad platform support.
Tesla first showed the iOS App running more than six months ago, and it seemed pretty complete then. I really hope the delay has been getting an Android version ready as well, because judging by OVMS figures, Android users are at 50%.