This is just better and more customizable binding for my customizable phone holder (https://www.thingiverse.com/thing:2412017).
You can set length of arm between handlebar and holder and choose from 2 types of handlebar affixers and 3 types of arms (two_parts type allows you to turn the holder by 90 degrees).
You will need some M3 screws and nuts (count and length depends on your variant of model). The two_parts arm needs also one M3 screw and nut.
Check your model before printing if using two_parts arm - there is a risk that nut hole is too deep. In that case consider bigger arm_length and / or smaller tooth_size.
I haven't tried to print it yet but I hope it'll be working.