I am using adobe ideas for my doodling and no lag at all.
The lag is on doodle buddy app go and check it out it's free
Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)
Here's the guide
https://forums.macrumors.com/wap/GetThread.php?t=1344247&bat=
This has nothing to do with the OP. Start reading the OP's, thank you.
video is fake
Well if it actually had anything to do with the hardware, those tips would be what you try to help.
Hardly worth calling him out on, just trying to help.