Musubi is a social platform for mobile phones. Musubi connects friends using the phone's address book to support pairwise and group communication in a "feed" using text, photos, and voice.

Musubi is also a platform for building social applications that can also participate in a feed. Using the SocialKit library, developers can write apps such as turn-based games or real-time collaborative programs. SocialKit helps developers write these apps, and Musubi helps users discover and use them.