Is it possible to write android application using Google Web Toolkit? We are writing simple web application using GWT(Google Web Toolkit).  Now we should have this application cloned on Android and iPhone. 
I don't know about the iPhone but may it is possible to have  same GWT application running on Android?
Yes

Most Android browsers support Javascript quite well, and since GWT "translates" the Java to Javascript it should be fine. Obviously it might require some tweaking to accommodate the screen formats.

EDIT:
Note, it will be a web application, with all limitations that come with that