Keep Alive is an app that the Windows Phone 7 homebrew community is familiar with, but it has now been accepted into the Windows Phone Marketplace so everyone else can try it. The application was created to solve a problem with Windows Phone 7 where WiFi is unavoidably disabled when the device goes into stand-by. While this ostensibly saves battery life, any apps that use push notifications will force your device to use mobile data, which actually uses more power, and eats away at data caps. Hence, Keep Alive works by forcing the device's WiFi to stay active while in stand-by.
As to the application's efficacy, I have just installed it on my Lumia 800 and will monitor over the next few days and report back.
By the developer's own admission, the submission of the application is "sketchy". If you visit its Marketplace page, you'll see the app is defined as,
"Quick reference with CPR details for infants, children, and adults. Useful to have on hand; you never know when you'll need it!"
The Marketplace page has a screenshot to match, which has no resemblance to what actually runs on users' devices!
This sleight of hand raises serious questions over the Marketplace.
Firstly, why should a developer feel like they have to sneak such a simple application into the Marketplace?
Secondly, and most importantly, how could such a spoofed application pass Microsoft's quality assurance?