Hi,
I am a developer, i build script extension and plugin for after effect and all adobe products, a plugin is built with c++ language for after effect, you can manipulate the pixel using it, a lot of people think extension is a plugin, if you want example of extension that i built, i can send you some example, but for plugin, you need to contact me, and send me the requirements, and i can process your request and see if i can work in your plugin, plugin is more difficult.
best regards
Adil