Open-Source PPI & Online Measuring Resources

Greetings!

I am building an application for the Android platform only to measure the size of digital objects into inches and centimetres. I have designed its basic user interface and according to my superiors, I should integrate open-source measuring resources like this app https://ruler.onl/ with my application instead of deploying all features from the scratch.

Although it is a piece of fine advice but I am not sure where I should find such pre-built resources. Actually, I am using Kotlin as a language that is why I am facing problems while finding the supporting material.

So, I would be grateful if you share any communities or platforms in this regard.