Afraid I won't make instructions - they're a pain to make for very little return, and a lot of the construction steps could be inferred from looking carefully at these three pictures anyway.
My Mum has requested that I make a phone stand for her as well, so that's my next task!
I do have a tripod MOC, but it wouldn't work very well for a phone...
Maybe you should make one yourself! The grip would be the most fiddly part, as it'd have to be freely adjustable but also strong enough to remain in one position.