Circular Design Guide - Toolkit that brings design thinking full circle
Splitwise - Splitwise is a free tool for friends and roommates to track bills and other shared expenses, so that everyone gets paid back. On the web, iPhone, and Android!
Design for Startup - Everything about design for startups
Dinngo - Splitting payments the fun and easy way
Text A Coder - Send a text, get a developer and project manager instantly
/Tab - The simple way to split a bill among friends.