I'm new to AppGameKit and couldn't find this information anywhere, is there a way to use BASIC and C++ in the same program? Or do I have to fully commit to one or the other?

It would be convenient to use the BASIC API for general game dev and call C++ code for native functionality only when needed.

Tier 1 (BASIC) supports plugins which can be written in C++ and this sounds exactly like what you want. There's an example plugin project in the install folder.

I found this page, which I assume is what you were talking about: https://www.appgamekit.com/documentation/guides/14_plugins.htm

Looks great! Are there any plans to add plugins for mobile and/or HTML5 platforms?