Review: Samsung Focus S for AT&T
The Focus S runs Windows Phone 7.5 “Mango”. Because licensees aren't allowed to modify the user interface, the Focus S runs menus and software that are identical to that of the Focus Flash. It looks and behaves the same as other Mango phones.
The unlock screen includes a set of notifications at the bottom that let you see missed calls, emails, and messages. They are easy to jump into once you unlock the phone. There aren't any cool lock screen features that take you directly to your inbox, though.
The home screen is made up of dynamic, Live Tiles that update their content throughout the day. You can pin applications to the homes screen in the form of Live Tiles — some active, some static — where they can behave, in effect, like widgets. I takes a little bit of time to grasp the concept, but after a while, it's really neat to watch the Tiles do their thing.
The Metro interface of Windows Phone requires you to swipe your finger to the left to discover more content/info in most apps/menus you happen to be using. For example, swipe to the left from the home screen, and you go into the main menu. The main menu is where you’ll find the full list of apps, settings, and other tools.
Most individual apps can also be tweaked a little bit. Mango itself supports multitasking, or fast-app switching. Press and hold the back button, and you'll see a collection of all the recent applications you've used. Simply pick the app you want to return to, and you'll jump directly there. Mango preserves each apps' state, so when you return to it, it will be exactly where you left it.
As far as performance goes, the Focus S is extremely light on its feet. It never felt slow or bogged down.