UV Outliner - UV Outliner is a small and powerful single-pane outliner.

Orgzly - Outliner for notes, tasks and to-dos

Remember The Milk - Remember The Milk is a task and time management application for mobile devices.

Notin - Notin – notes in notification app helps users in creating alarms to get reminders about important tasks right on the home screen.

Planka - Planka is an open source project management software similar to Trello.

Light Notes - Light Notes app features options to help users easily taking notes to remember important details and instructions. You can add new notes by entering the title, description and selecting the tile color according to the priority of the task.