Documentator - We make documenting your product a piece of cake 📘
Pocket Lists - World’s Friendliest To-Do List App
UnMarkDocs - Unleash the Power of Markdown to Write Better Product Documentation
UpNote - A beautiful and clean cross-platform app for notes organizer
You Need A Wiki - Create a wiki with Google Docs
Synology Note Station - Without needing to spend money on Evernote, Synology Note Station provides a desktop client to organize all your random notes in one place.