First off I must tell you this is not FREE. While I am all about free- this $15 App is well worth the money since it works the same as a $99 Apple TV. (This is available for PC or Mac)!
You can connect more than one device at the same time!! But only iPad 2 and up or iPhone 4S.
reflectionapp.com - $14.99 - to project your iPad 2 or iPhone 4S - it's GOOD!! Hope this was helpful! See ya!!