As a teenager, I loved solving Nonograms in puzzle magazines on train rides or when I was bored, they are the perfect time killer. Somehow I forgot about them but recently rediscovered them through a Twitter post, which was a real pleasure.

The linked website seems to be very nice, especially since there is a community aspect to it, where people can send in their own puzzles (it seems like).

My recent goto app for Nonograms is https://nonograms-katana.com , which works great on browsers and mobile alike with lots of well thought-out features (e.g. it asks you if you want cells automatically crossed out if a line is complete) and beautiful artwork, good interaction, etc.