On Facebook, Words with Friends, Farm Town (not Farmville, which always rather sucked in comparison), and now Candy Saga.
On Chrome – Angry Birds. Yes, I first got this for my son (for free), but I admit to playing it sometimes! It’s difficult!
On devices that I don’t own but use occasionally – Scramble with Friends (no app for PC – annoying!).
Other apps that I would use if I could –
LibraryThing.com (actually, I don’t know if they have an app, but I am on the website all the time. I have had a paid account there for over five years.)
I used to have a weather app years ago on a previous laptop. I was a meteorology major for a year of my life – nearly twenty years ago now.
Ah . . . I do use an Adobe Digital Editions app (or is it just software?) to download books from the library in epub format and load them onto my Kobo.