For the record, I am a PC/WACOM/Corel user, but found this amazingly inviting. If only IPADS came with external storage ports. Some of you will know what I mean and why.
Anyway, I am passing along this video I located so that you can check out the useful IOS app for yourself. I think you can purchase it for around $7.00 U.S. online which is hugely less than the cost of Photoshop or Corel Painter. The intro music will end in about 1 minute, then you can hear the author of the video.