BookStack
Description: BookStack is an open source knowledge management platform to help build and organize wikis for internal or public use. It allows you to collaboratively write and structure documents to organize knowledge, notes or documentation.
Type: software
Pricing: Free
Kik
Description: Kik is a free instant messaging app for mobile devices that allows users to chat with friends using text, stickers, gifs, and more. It's especially popular among teenagers and known for its anonymity features.
Type: software