I did it one time with a pelvis area harness instead of the feet-hanger shit so I didn’t go upside down. It was like a carnival bungee jump thing that was about 80 feet high, cost $25 to do. It was scary as shit for the moment of falling but once the bouncing started it was pretty dang fun.
TLDR: Don’t use phone apps
(I did actually read it so TLDR is inaccurate for me)