Haven't used Google Fit, but their My Tracks app records a GPX file which has the data to build a map and your speed at every point along the way. My Tracks can pair with a couple of specific BLE HRMs but won't show you basic stuff like your current speed during an activity. But you can upload it to Garmin Connect or whatever, and get a map and charts of your ride. It's pretty limited, but, still, the price is right, and if somebody is in the market for a bike computer anyway, having some experience with a free one is probably beneficial.

Here are some screen shots from the Google app store.