OK, I think this app is ready for it's alpha release...do I need to ask the mods or anything before release? It just uses the track JPG's provided by Scawen...
Oh but I have It's looking good, I'm just reserving judgement until you've fixed the things you've said you'll fix...
An interesting feature might be, though, to allow a left-click to add a "pin" which has a pop-up balloon giving it's co-ordinates (i.e. to mark several points at once).