If you haven't already found this fun toy making app for Android and IOS, then you may be missing out. Build your own LEGO Bionicle style creatures and heros from your smartphone. Creations can then be printed on your own 3D printer or ordered through an online maker service. Some of the features I enjoy is the textures you can choose from for individual parts as well as choice of colors for plastic. The selection of parts is decent, but any custom parts you might want, will have to be modeled in outside software platforms. I'm waiting to see what compatible part files start showing up on thingiverse.
Here's a couple screenshots from my phone...
The model can also be scaled up or down before printing, up to 300%.
Tinkerplay in action.