Spam calls waste time and compromise privacy, yet most blockers monetize through data sales. A decentralized reputation system could let users flag numbers without central data collection.
Develop a lightweight app that verifies calls via community reports while keeping personal data local. Use cryptographic hashing to share spam signatures anonymously.
Monetize through paid features like premium blocking lists or business verification badges rather than ads/data sales.
MVP: Simple call screening using existing open-source blocklists with optional community reporting.
Risk: Bootstrapping network effects against established players with large user bases.