wger (ˈvɛɡɐ) Workout Manager is a free, open source web application that helps you manage your personal workouts, weight and diet plans and can also be used as a simple gym management utility.
Oppia is an online learning tool that enables anyone to easily create and share interactive activities (called 'explorations'). These activities simulate a one-on-one conversation with a tutor, making it possible for students to learn by doing while getting feedback.