Cover is contextually aware. As it learns, it begins replacing the default set of six app launch icons on the left side of your lockscreen with relevant ones. For example, perhaps it learns that you text a lot while driving (naughty, naughty). You'll see your SMS app there, once it figures that out.
Or it might understand that you use a certain email client at work. The same thing will happen.
Right now, Cover is in invite-only beta. Folks with Android 2.3 (yes, that far back) or greater can request access via a form on Cover's website. Assuming you are accepted to the beta, Cover will add you to their beta test tier and you'll see the app in Google Play. The app is and will be free, but Cover plans to make money by spotlighting new apps, promoting ones that users have installed but not used, or perhaps even by licensing the app to smartphone makers, a la Swype.
Cover is, of course, an app that can be done on Android and not on iOS. At least, it can't be done on a non-jailbroken version of iOS.
Cover's CEO Todd Jackson added that Cover's use as a lockscreen replacement might just be the tip of the iceberg. When it (hopefully) eventually monetizes, it could be by suggesting apps for the right occasion that you haven’t even downloaded yet. Now that is smart discovery in a nutshell.
As an example:
Imagine going to a tech conference where you didn’t know there was a schedule app. Cover could see everyone else in your vicinity is using it, and suggest you download it too. Loyalty app companies might pay to have their apps suggested when you’re at restaurants they work with. Or if you’ve been playing games for 20 minutes, Cover might recommend other apps by your favorite developers…if they pay.Interestingly enough, the TechCrunch writer found himself jealous of Cover's abilities, as he usually uses an iPhone.
The iOS lack of customization has always made us say that for non-techies, iOS is the way to go, but for geeks and experimenters, Android is the OS of choice. Cover just confirms that, again.