I think this is already well covered with all these apps that share your location in several services.

SMSCON is kind of private app between you and your phone. Nevertheless, it is in our plan to use some code from snuggle to allow a cheaper on battery tracking or as a fall back when GPS is not available (like inside a building etc).

On Snuggle, I have worked a lot and add many more features in the backend like a daemon logging movements and an sql database for storing and extracting the movements in files that can be uploaded to sites that give you your tracks in a map for a given period of time.
At the moment all is not that user friendly and need some time to make some UI for configuring and initiating those actions.

It is just that I am such a slow coder..