Here are some of the plug-ins I made with Rorohiko's Active Page Item Developer. APID is a terrific tool that resolves the shortcomings that make 'pure' ExtendScript less viable for professional development.

Remember Document's Position
Saves and restores position of each document

Check profile
This is a very handy plug-in which checks color settings, in InDesign and Photoshop, whenever a document is opened and gives a warning when they are incorrect. In our workflow, we use two color profiles. In the past, I sometimes used to forget to turn the correct one on. It's no longer the case, after I made this plug-in. I posted the sourse code here so that you could remake it to your needs: enter your color settings, messages, etc.