I hope you don't mind, I took the liberty of converting your support ticket into a public forum thread so everyone can benefit from our answers to your good questions/
"functional testing of DLL/Class Library" is usually referred to as "unit testing". I am sorry but Test Studio is not the right tool for this sort of testing. Test Studio is designed for functional/UI testing of a web application or Silverlight application or WPF application (or performance testing or load testing).
For mobile platform testing, we have our Test Studio for iOS product that might meet your needs.
the Telerik team