body: I live in US and I am a freelance developer.
  
  
  If I take a popular yet generic Android app (such as a calendar app or a note taking app) made by a company in United states and make an app which looks almost similar to it, with the same User interface and features, but without using any of their content (such as images, music, etc), is it considered legal?
  
  
  What if I make the app a non-profit freeware (no ads, no purchasable content) ?
  
  
  
title: Is copying the User Interface and features of an Android app considered illegal in US?