So you have a spare bike that you would like to turn into a rental bike? AirDonkey can help. It is a smart kit with a lock that you can lock or unlock from the Donkey App. You can take a picture of your bike and create a profile for it on AirDonkey to start renting it.
The process is simple. People who need a bike can use the app to locate bikes near them. At the end of their rental, they will just have to leave the bike back in the drop-off zone, and lock it. Yet another interesting Kickstarter project.