Unless it's for something fairly trivial, I generally don't use free apps.
When I do buy an app and have a choice I generally will go with the iOS version. I haven't given it a lot of thought, but I suppose it comes down to a couple of reasons.
1. I have never really trusted Android. Probably because it's made by an advertising company and as time goes by, the ad supported business model is starting to feel more and more unhealthy to me.
2. Android apps are rarely as polished as similar iOS apps. Even for relatively basic things like layout or color scheme, iOS apps seem to have more care put into them.
