SLOWLY - Make pen pals from your smartphone
PenPal World - Connect with people all over the world
Penpal Café - Find a person you can share your observations with.
InterPals - InterPals is a friendly community of over 5 million friends, language learners, travelers and penpals.
Plane.so - Open-source project management tool to manage issues, sprints, and product roadmaps with peace of mind.
Polyglot Club - Polyglot Club is a new social network for language learners.