How to effectively use ODK Sensors in my under developement Android app?

Hi everyone, the title of my topic is quite self-explanating:

I am developing an app that needs to read data from a sensor connected via usb or bluetooth, and I thought of using ODK Sensors Framework to ease the process.

Initially I thought that it was like an API, so I looked for libraries to install and methods to invoke in my source code.

After a bit of unsuccessful researching, I figured ODK Sensors Framework comes in the form of an apk, and from here my question: how do I make use of this apk in my code?

Also, is there any documentation regarding the methods I can use?

Thanks in advance,