What are some alternatives?
When comparing Tweek.so and Todoist, you can also consider the following products
Teuxdeux - TeuxDeux / What deux yeux have teux deux teuxday?
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.
Google Calendar - Spend less time managing your day & more time enjoying it
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.