Here is a free tool where you can check whether your blog or website has a responsive theme or not. Or to test out your responsive template/theme to make sure that it works out perfectly on a smartphone or a tablet.
1. Go to: http://www.responsinator.com/
2. Type in your site URL and click on GO button.
It will show to you how your site looks like on:
iPhone 3+4 portrait · width: 320px
iPhone 3+4 landscape · width: 480px
iPhone 5 portrait · width: 320px
iPhone 5 landscape · width: 568px
Crappy Android portrait · width: 240px
Crappy Android landscape · width: 320px
Android (Nexus 4) portrait · width: 384px
Android (Nexus 4) landscape · width: 600px
iPad portrait · width: 768px
iPad landscape · width: 1024px
Kindle portrait · width: 600px
Kindle landscape · width: 1024px
Here is another site where you can test your responsive design created by Matt Kersley.
1. Go to: http://mattkersley.com/responsive/
2. Type in your URL and press Enter key.