Researchers from several institutes worldwide recently developed Quarks, a new, decentralized messaging network based on blockchain technology. Their proposed system could overcome the limitations of most commonly used messaging platforms, allowing users to retain control over their personal data and other information they share online.
Electronic voting, maybe? But for most cases a transparently ran centralized ledger should work better.
electronic voting is a bad idea regardless of any blockchain integration
Voting on a blockchain is a great way to enable outright purchasing of elections. If I can prove I voted a certain way, I can sell my vote.