ProductiveApp.io - Productive is a habit tracking application.

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.

Streaks - The to-do list that helps you form good habits.

Drag for Gmail - Transform Gmail into organized To Do lists (like Trello)

Strides - Track all your goals & habits in one place, with flexible reminders to hold yourself...

KanbanMail - A Kanban board for your emails.