This was one program I was making for months with Game Maker 8.1.

(current screenshot of the program; may change some time later once per update)
Update: 3/19/2014 - I just added the grid (which can also overlay the parts) and added four slots for importing more parts.... still working on that one, though. And added two mirroring buttons.
...aaand I need to make the outlines of the parts wider, and add ones that are filled too.
Don't know what it is for? It's for making easy animations... but with a catch: you only do the character model's lines and/or the parts appear roughly drawn, so you need to draw them over to finish the sprite completely.
The sprite you see in there... well, it's just a little example... I still need to add more parts on this project, such as a realistic head and hands with different angles, and a feature to upload more parts to the program to make it work.
--Speaking of features, here's what it has currently--
Spoiler, click to toggle visibilty
-X and Y adjusting
-Angle
-X and Y Scaling
-Visible (useful if you are in need to do something to the character like animating a bomb appearing in their hand)
-Alpha (AKA Transparency)
-Depth (trust me; you'll definitely need to use that one)
-Color (to identify an identical part with another color)
-Camera Rotation (useful for making falling animations...)
-Background color changing
-Camera (to save frame; still need to be tested)
-Saving and loading animation (still testing)
-New file (of course!)
-Adding frames (removing frames is being tested; it currently removes the last frame instead of the current one)
-Play Button (and stop)
-Changing name of part
-PARTS! (well, only bits... still need to add more!)
-Image Index (that one's used to change to different shapes of that part; like changing a hand's fist to a peace sign, for example, or for changing a head's face or expression)
-After-Image (ya know... like Fighter Factory's OnionSkin...)
There are still things I need to add in and fix too...
Spoiler, click to toggle visibilty
-Importing extra parts
-Saving and loading with imported parts
-Need to make MORE parts
-A function to turn ALL frames into pictures (there's still the Print Screen fucntion, though...)
-Making the current frame become removed instead of the last frame
-Adding MORE parts, such as a realistic template of a character (male and female)
It only supports Windows, if anyone's gonna ask...
Dunno what else I should try adding or remodifying. You can suggest me what I should add in this program.
OR, maybe ask some questions...