Chopstix uses the RICE model to allow you and your team to prioritize features or tasks. Each member evaluated the Reach, impact, confidence, and effort to create a score for each entry. The features are ordered into a list to help you determine what the low hanging fruit is and spark conversation among the team.
Hygger - Hygger - is an Agile project management tool with built-in prioritization.
Documize - Enterprise-grade wiki and knowledge management platform
Planka - Planka is an open source project management software similar to Trello.
HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.