Astrid is a social group productivity platform that helps people get stuff done with engaging reminders and social pressure. It is simple enough for the casual list-maker but scales to the GTD life-hacker. It is used by college kids to share workouts, busy mothers to families, and business teams to manage companies. Users share goals from an iPhone, Android or web app privately to friends or colleagues, or publicly on Facebook or Twitter. Invited guest can add or complete tasks, comment via email and monitor progress with mobile notifications. Astrid generates revenue with premium versions for businesses and by matching unmet goals with related products and services.