** Pre-cache tiles in adjacent areas and possibly zoom levels
* Improve texture cleaning algorithm
* Show a notification when we are loading tiles or saved data
-* Display length and duration of track
* Display movement speed
* Display location accuracy
* Show a better visible marker for the current location, possibly also indicating movement direction/speed
* Smooth animations for zooming, probably using some WebGL magic
* Use available larger/smaller tiles with resizing as loading placeholders while zooming in/out
+* Find better UI for track length/duration display
* Better GPX saving implementation [blocked by missing web APIs]
** Set file name to save into to a good default (date + maybe some location name)