marketplace -- A decentralized e-commerce marketplace where one can upload products and also buy a product.
Lottery -- A decentralized online lottery where there is a single manager and multiple players
Campaign -- A decentralized bidding or crowdfunding platform. Multiple managers and multiple users who have to donate money to the campaign to be able to become approvers. All money contributed is locked down by the contract. For the manager to use it, he has to create a new spending request, and only when the request gets the required number of approvals from the approvers can the money be released
Tweether -- A decentralized twitter;