FileProInfo - It's All About Files, Software, Online Tools - 100% Free
UserGuiding - User onboarding made easy, for less. Create product walkthroughs in a couple of clicks, without breaking the bank.
File-Extensions.org - Large computer file extension library with detailed explanation of each file type with links to download free or associated software programs.
Usetiful - Fight user churn with great user onboarding. Interactive product tours and smart tips significantly improve your user retention.
GroupDocs - GroupDocs is a web-based service for online document sharing, collaboration and management.
Userlane - Digital adoption platform with interactive guidance for software applications allowing anyone to understand and master any software from the get-go.