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

Tasker - Tasker is an application for Android which performs Tasks (sets of Actions) based on Contexts...

GoodTask - Task manager based on iOS reminders and calendars

Automate - Automate various tasks on your Android smartphone or tablet.

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.

Locale - Locale helps content owners and translators work together, so Rails developers are free to write more code