I would like to introduce the tool for game developers I am currently running a pretty successful Kickstarter for (funded within 17 hours, currently approaching the 2. stretch goal - a Mac version):
Sprite DLight on Kickstarter
The tool generates bumpy normal maps for dynamic lighting effects in games, based only on already existing 2D sprites.
A quick comparison of normal maps generated by common tools/plugins to those of Sprite DLight:
1: Original "Sprite DLight Title Art", ©2014 by the amazing artist AlbertoV from DYA Games
2: Normal map created by the GIMP plugin (same as PS plugin)
3: Normal map created by a common normal map generator with the original sprite used as height map, followed by shape enhancement
4: Normal map created by Sprite DLight in one click
3. is the best result you can achieve with current automatic normal map generators combined with clever techniques, although the result is still pretty poor, it's more of a bevel effect, which is randomly concave or convex, particularly at the edges of the shape.
In the "Updates" section, there is already a pretty straightforward guide for the technical integration with Unity, including a step-by-step video.
"Ghost Pizza", ©2010-2014 AlbertoV (DYA Games), normal map generated by Sprite DLight, dynamic lighting preview recorded in the Sprite Lamp shader
There is some time left to get in on the beta and to make the Mac version and some more stretch goals possible.
I would love to get some feedback on this, and I can't wait to see your 2D games with dynamic lighting!