Fuse - Fuse is a UX tool suite for mobile app designers and developers.
Product School - The global leader in product management training
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!
The Product Folks - A volunteer-led community of product managers and makers
GoodBarber - GoodBarber is a mobile app creation platform.
The Product Management guide - A book on how to create and ship products that people love