How to take a screenshot of your computer screen with an iphone/ipad?

I found something cool but i want it on my phone, and it's not letting me save it on my phone, how can I take a picture of the screen and make it look realistic?

Step 1. Get this program called "Gyazo"
Step 2. Use it to take a screenshot of your computer screen.
Step 3. Plug your iPhone/iPad/iPod into your computer
Step 4. Say you want to access the pictures and photos of your device(s)
Step 5. Drag the picture you took with Gyazo into your iDevice