Here are different projects I incurred in programming with API - C language, learning, and applying on different platforms. In pdf files, you can take a look at the codes I wrote

​

I've created an example of usability. If you are interested, here is the video link: 

VR-technic

https://youtu.be/uMxhU2Dfe4I

The socializer

https://youtu.be/hEsOsxkepd0