Had Todoist just for just a couple of days before I bought the Premium. Really like the program! To my surprise however, I had to look around a bit to find out where to click to begin the upgrade process. Most programs are constantly showing or reminding of the upgrade option. Todoist seems to be the opposite. I would suggest the upgrade option be a little more visible or easier to find.
Also a question, is there a way to submit suggestions such as this one without doing what I just did (go through support)?