Beautifully presenting web pages and apps in context can really help draw in potential users. This typically consists of placing screenshots in browser windows, phones, etc and it usually done in Photoshop. Using CSS mockups are a great way to showcase your app design in modern and interactive way. If you are looking for solution to turn static mockup into interactive one, here are 25 Cool Pure CSS Device Mockups to demonstrate your user a real-life user interactions.