simplicity and minimalism. focus on what really matters: do.

It is your choice in how simple or complex you want you to do's to arrange. In any.do you can basically decide yourself. Either creating to do,s by just typing and dragging and dropping. Or creating recurring tasks, with notes, attachments, sub to do's etc. You could also divide your to do lists in more themes (work, personal, charity). To me it gives the same feeling as writing and striking out on paper, without having to bother with paper and all the related problems (the dog ate it)

I love that the user interface is minimalistic and beautiful. Makes it very enjoyable to use.