OS X 10.11.3 update fixed the crash.
I’m a happy Pace user again. The app hasn’t been updated in a while, and it was crashing on launch in 10.11.2, but the OS update to .3 fixed it. So I’m back to using Pace every day as a reminder to stop slouching and get up and move every once in a while, and it works great.
portalkeeper about Pace