For today’s todo stuff i used to make a file named todo.txt on my desktop and write down the stuff which i need to complete today and deleted the stuff which is done, which i was comfortable using it. I was looking for some extension on extensions.gnome.org , i came through this awesome app, which i think was first released in 2006 on lifehacker. But i came through this few days back. What this app actually does is create two text files on your system name todo and done, and store all your task their and show those stuff graphically. I really like this idea. For today todo i use this app and for every thing else i use google keep, which also very nice app. Both the app are available for mobile also but keep is free and for todo.txt you need to few bucks.