I'm looking for a GTD (Getting Things Done) app for Android that has the following features:
Lightweight and easy-to-use (no need for feature creep)
Possibility to sync the tasks between devices and/or access the tasks from a web browser (this is mostly to ensure that tasks are backed up continuously)
Possibility to schedule the tasks in a calendar, where tasks past the due date are automatically advanced to today's date
Widget, showing both "to do" tasks and "past due date" tasks
Does not require a monthly fee (it's ok if the app is non-free, though)
This is not a duplicate of this other question since the requirements are less strict.
So far I've tested Chaos Control which fulfills all these points; the only doubt I have is that it's made by a small company, so there's always the risk the project might be abandoned at some point.
I've also tested Trello but wasn't satisfied by it because of its complexity and its lack of a calendar.