By compressing the data on their own servers, those on limited data plans can see genuine savings, the company says. The sorta open beta is still limited: Although it is easy to sign up and gain access, only U.S. users can enter the trial for now. Also, only users on Android version 4.0 and higher can enter.
Opera sets up a Virtual Private Network (VPN) and funnels that data to its servers. Notably, the company measures all of the data coming through your device, as well as how much you save, but the company says that no data is scanned -- they are not the NSA, after all. To be clear, only unencrypted data is compressed.
Signing up is pretty easy. You won't "find" the app in the Play Store without jumping through a few hoops, though.
First, you sign up at the company's Google+ community page.
After you do that, you can then opt in for the beta test here.
At that point, you will be given the opportunity to download the app from the Play Store to a supported device -- obviously WiFi-only devices don't qualify.
While those on iOS, Windows Phone, and outside the U.S. need not apply, the company said that it is working on getting the app on other platforms and in other countries, as well.