MadAhead - Co-write stories, poems, etc. Debate, discuss or create fun conversations.

Zuunote - A web-based and Markdown-based note-taking app that's reimagining writing experience in Markdown that everyone can enjoy.

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

Typora - A minimal Markdown reading & writing app.

Taskful - Deadlines, meet your match.

Obsidian.md - A second brain, for you, forever. Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files.