Honestly I've never had a need since my tablet has HDMI out.
There is value in a wireless app, if only because of flexibility and ease of use.
For example: A couple of our faculty have used an iPad + AppleTV combo when giving lectures - having an HDMI cable dragging around would be less than optimal in that situation.
If there's a reliable way to replace that iPad with an Android device, it would open up the tech to some other faculty who own Android phones and tablets.
BTW the PlayTo app appears to be more of a DLNA-style application - it supports AirPlay, but likely only does so in limited fashion. However there's a try-before-you-buy version of the app available, so you can try it out to see if it does what you want.