Achievement SS is an addon that takes a screenshot whenever you get an achievement. The addon has a 1 second delay before taking the screenshot, it can be changed in the Lua file by replacing "local delay = 1" with whatever number you want.
There aren't currently plans to add additional features, this addon is solely for taking a screenshot when you earn an achievement, but feel free to make suggestions under the comment section and they will be considered.
Changes:
5.4 - Updated TOC for patch 5.4
4.0 - Updated for 4.X
2.0 - Updated for 3.3.X and added a 1 second delay before the screenshot is taken.
1.0 - Initial release