WP Responsive Simulator
WP Responsive Simulator gives you a great way to demo your products and mockups online in a fully responsive way. Let your client view your design and see how it reacts to different device sizes with the click of a button. Secure your demo links using WordPress’s online permalinks so your demo directory is never visible to the end user.
Preset with common screen resolutions from mobile to large format, but you can also give them a way to add new resolutions to their preview. Your user can simply drag the resolutions around or add their own.
Need additional protection? Add another layer of security by using WordPress’s built in password protected page feature and allow only users with access the ability to see your work.