No obvious way to contact him on the app store. This app read -110° heading on my Vivoactive when I was westbound, thought he should know. Works great though, even at over 500mph.
If he doesn't see this forum post, you could try private messaging tostr in the forums. Right now, the app store doesn't have a mechanism in place that allows users to contact developers for bug reports and feedback, but it's something we plan to add in the future.
