Works, but with issues

This app does not work as well on my iPhone 5 as do the rest of their apps. The problem is that it doesnt pick up the up/down motion. That means I need to shake the phone to register the pull-ups I do. Not a deal-breaker, but an annoyance.

Trane Francks about Runtastic Pull-Ups PRO Trainer, v2.3.1