I tried Treesketch because I now have an iPad Air. It is an awesome app. However, I bought the iPad to use Procreate. That's an awesome drawing app, pity about the iPad's totally chronic pen screen tech. As for iOS, well that's a bad joke compared to Android. I had to get a Samsung Galaxy Note 2014 2.3 GHz quad core in the end. The iPad is useless for drawing but the Samsung is an awesome drawing computer. I did find a use for the iPad in the end though so I'm keeping it. I'm running Lemur which is a music controller so I still have Treesketch. Not sure if I'll ultimately use it but it's very cool.