Series - Super cheap when on sale. Colored puzzles. Has choosable difficulties
Travel Mosaics: A Paris Tour
Series - Super cheap when on sale. Colored puzzles. Has difficulty options you can choose.
There are more than 10 games, but some of the later ones have issues/changes.
Hungry Cat Picross
Meow Tower: Nonogram
Pepper's Puzzles
Voxelgram
Steam recommendation. There's over a thousand puzzles on the workshop, and the ingame interface makes downloading and playing them easy.
Picross S
Series. Mega puzzles use the same puzzles as normal, just with different clues. Take a long break before doing those so you won't remember the answers.
Khimera: Puzzle Island
Cupid Nonogram
Piczle Cross Adventure
Pixel Puzzle Collection
Paint it Back
Picross e
Series. Very polished for a quick puzzling experience.
Murder by Numbers
Visual novel hybrid. Only recommended if you like the story. There's no pure puzzle mode.
Pixel Puzzle Makeout League
Visual novel puzzle hybrid. You can skip the cutscenes!
Piczle Colors
Pokémon Picross
Added for the daily speedrun challenge. 5 7x7 puzzles in 2 minutes. I enjoyed doing those for a long time. Game itself is okay.