Do it yourself.
Centriphone is a simple camera mount to produce bullet time effect on a budget, using smartphones or action cameras.
Find all information, plans, files and instructions to build and operate your own Centriphone.
The printable 3D file
Simply print it.
The Cardboard version
Draw, cut & paste.
The Coat hanger solution (AKA Matt & Kim's version)
It doesn't get any cheaper.