when you convert our text files to CDV and import them into the program, what do you select on the drop down menu (data profile)? So, I take the text file from pilot app off my ipad, convert to csv with litchi, then import. Im not sure what to select. I tried flytrex but the MPH is way off.
Phantom Overlay is an app that easily allow you to add GPS overlay on top of you video (examples)
It generates GPX files that you can use with Garmin Virb Edit to add nicely designed overlays.
Or generate FCPXML files for simple import into final cut pro, to display GPS info as text on your video.
And you may check the KML files in Google Earth.