By displaying the paths (both in the KML / GPX and on screen within the BBtracker App) in colour you can present another axis of information to the user. A simple colour gradient can be created; where Red is the slowest speed recorded and Blue is the fastest. As the track is recorded, the current fastest speed can be normalised to 1 and the path displayed in colours of the spectrum from fastest to slowest.
This would be of great use to those who use BBtracker for fitness or sport activities because it would show at a glance where they were slow relative to other places along the track. It would also be of interest I’m sure to many other applications.
As an extension of this, the axis of the track displayed as colour could be configurable. Some people may find it more useful to display altitude as a colour so they can infer the height if the track on a 2D display. (this should be less important in KML / GPX as I presume BBt will eventually export full 3D tracks anyway) Other users may prefer to log time as a colour change on the path so that it is easy to understand the direction of progression on complex paths. An open extension could be created that would allow the app to poll a secondary source of data such as an attached thermometer to record temperature over the track or perhaps radio signal strength
