It's really frustrating trying to find a free place to park in Washington DC. Would be great to have a mobile app that could show you free spots around. Could be based on public webcams, data from parking lots or maybe people can somehow show click in the app they are leaving the spot so someone else can use it.
Rough operational flow:
1. User starts app on phone or tablet
2. App verifies that the GPS is activated
3. User registers or logs in
4. Outgoing parking space user can either click a button to indicate they're leaving the spot now or they can click a button to set up a future time when the space they're currently in will be vacant
5. Incoming parking space user can click a button to locate a desired space and put in a request with the current holder for the space by coordinating a time to hand off the space
I've developed some user stories.