Postcrossing - A postcard exchange project that invites everyone to send and receive postcards from random places in the world. For free!
Gemini - Gemini is a web-based project management platform that supports for issue tracking, bug tracking, test management, help desk.
swap-bot - Swap-bot is a online service that organizes group swaps and a community of creative individuals.
B21 Invest - Crypto investments simplified
Random PenPals - Get a quarantine PenPal in 10 seconds
Nash - The easiest way for any business to offer same-day delivery