After my wife (the organized one of the bunch) died, I was at loose ends. I am computer-savvy (I first ran one in 1963 -- punch cards and all), but I bought my first smartphone then (my daughters insisted) and I discovered Todoist. It immediately let me keep track of ongoing projects, and it got even better when I could use Todoist in my web browser and it automatically synced with my phone.

Even the quibbles don't diminish my five star review:
a) I cannot print the day's requirements directly; I have to use the computer's (MS) print screen dodge. I post it on the refrigerator to help me when I stumble out of the bedroom groggily in the a.m.
b) Why doesn't the web version not allow 1300 in the time box or else have the handy clock hands of the Android app?