How to set screen Web app for mobile web

Hello ,everybody
I want to create web app for SmartPhone but I don’t know about the set screen on web page for display on smartPhone is perfect

Is there a way or not?
help me please

thank you …

The “Designing a Mobile App” webinar shows a way to design layouts for smartphone and tablets using the iOS simulator and an Android VM.

http://documentation.xojo.com/index.php/Videos