Support for the FTC App Inventor development tool has been discontinued:

The FTC App Inventor tool has been replaced by the FTC Blocks Development Tool. The FTC Blocks Development Tool is a visual “drag and drop” design tool that is very similar to App Inventor. The FTC Blocks Development Tool is a built-in feature of the FTC Robot Controller app that is available on Google Play.

A tutorial on how to use the FTC Blocks Development Tool can be found at the following link:

Vuforia™ Software Development Kit Early Access

PTC has integrated support for external USB cameras with their Vuforia™ Sofware Development Kit. A pre-release copy of the software can be downloaded using the following link: