The concept is simple and effective. App 2 SD will automatically search all apps installed on your phone and you will sort them into categories.
You navigate and from three different tabs:
"Movable" means that you can move apps to SD card
«On SD card" apps already installed on your SD card but you can once again back on the phone's internal memory
"Phone only" apps that can not be transferred to the SD card
Behind each tab, you will find is the list of apps in question, their number and, below, a gauge that tells you the place you have left on the internal memory or SD card.
App 2 SD is actually a graphical interface that refers you to the settings for each application. You just have to touch an app icon and select the desired option: move the SD card or to internal memory of the smartphone. Do not expect however to be able to change the location of the native apps that are not transferable (such as Google Maps, Facebook or Gmail). App 2 SD does not allow it. Too bad.
You also have the ability to transfer multiple applications at once by pressing the "Menu" button on your phone. You can also delete all the files in the cache of your apps directly.
Finally, App 2 SD will notify you when the installation of any new application if it can be moved to your SD card.
As for blame, not much to report on our side during our test. But looking at some comments on the Market, it is clear that the application does not appear to function as a blocker pub (like AdBlock) is installed. Then the updates of some apps, once transferred, would no longer work. In this case, you can follow the advice of developers on their site here. I advise you rather at this point to reinstall the phone's internal memory the application before the update.