Sourceful - A search engine for publicly-sourced Google docs
Fuse - Fuse is a UX tool suite for mobile app designers and developers.
SatisMeter + NomNom - Turn your SatisMeter NPS responses into product insights
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!
CareKit by Apple - Open source software framework for creating health apps
GoodBarber - GoodBarber is a mobile app creation platform.