The application will be location-specific. If you lose something valuable, you can login to the application and list it as lost. As part of the requirements for listing, you will have to fill in a location, or several, where you think you might have lost the item. Also, you will be required to list any unique feature that will help in identifying the item. For example, if you live in London, England, and you lose your favourite jacket, you can fill in the districts you think you might have lost it - say Mayfair, London or Wembley, London and its unique features - say a frayed left sleeve and a bleached patch where the breast pocket would be.
If you find something that is lost, you can login to the application and list it as found. Also, you will have to fill in the exact location you found it and any unique feature that might help in identifying it.
The algorithm will sieve through the different entries it gets and match lost and found items that seem related.
You will earn points for every item successfully returned.
When the points accummulate to a certain amount, you can exchange them for cash, items, tickets, and so on.
The rewards, and the platform itself, will be funded with donations from people who successfully located their lost items on the platform.
If you lose something very valuable, you can place a bounty on it to increase your odds of getting it back. Such items will be displayed on a dashboard alongside the locations you might have lost them.
While the gamification will encourage people to help, the app's success will be reliant on people's goodwill. However, given the pain of losing something that most of us have felt, I believe there is enough of it out there for this to work.