PictureLogic — A solver and helper for a PalmPilot, and puzzle collections
http://​www.trefoilknot.com/

CrossPix — This uses plug-​ins for Netscape on Windows and Macintosh to give what I expect is a helper.
http://​www.libertysoft.com/​xpix/

StarPic Puzzle Game (FigurePic) (Paint by Numbers) — “Uncover the hidden pictures for hours of puzzle fun!” — A commercial site with a game for Windows, including coloured cells
http://​www.stargraphics.com/​star2.htm

Online Tsunami — Rachel Benn's Javascript-​based helper/solver and puzzle collection
http://​www.playtsunami.com/

World of CryptoPics - The ultimate Nonograms/Griddlers site and software! — “The ultimate Nonograms/Griddlers software” — A solver and creator for Windows, by Yariv Hastilow
http://​www.yarivh.com/​cryptopics/

Griddlers Net — “Extended Paint by Numbers online puzzles, new puzzles published everyday. Free fun.” — Includes colours and isometric puzzles; a community of solvers!
http://​www.griddlers.net/

Griddlers Solver - Editor and advanced auto-​solver for favourite puzzles. — A solver for Windows, by Juraj Simlovic
http://​jsimlo.sk/​griddlers/

QNonograms. Crossplatform nonogram solver & editor — An open-source solver and editor in C++
http://​qnonograms.sourceforge.net/