Hello,
I often use my phone to record « communting tracks » as a complement of my fr305.
But garmin connect cant handled the gpx file produced by the “my tracks application”
If some one want to have a look, a sample is attached ;)
I have an answer for you if you are still interested, made this work today.
You will need to manually edit the file...open it in a text editor (such as notepad, etc.) and replace this: