Fresnel sheet magnifier ($7 Office Depot), cut in half. It's really brittle so you have to take care when you cut it but it's worth the effort because it doubles the virtual size of your iPhone screen.
Hardwood block holds glass and magnifier in position. Has tripod screw in bottom to mount to the rig.
50mm - I designed this rig for this focal length and physical lens size. Any wider and you might get some vignetting, any longer and the teleprompter may be difficult to read.
iPhone running prompter app: I'm using the $9.99 Prompter pro because I wanted the remote control feature but i-Prompt is free and just as good if you don't need that feature
Matte box and iPhone support structure made out of black, foam-core board.
Everything mounted and held in relative position on a straight, flash bracket.
5D II and battery grip
Rode video microphone
Quick release on to a mid-sized ball head - no real room to attach to my 'real' video tripod but as this is designed to be used locked down that shouldn't be an issue.