Nokia Store is the official store for Nokia apps. This preview version is designed for use on S40 touch-and-type devices, such as the Nokia Asha 200, Nokia C2, Nokia C3-01 or the Nokia X3-02.
Among the options in this S40 version of Nokia Store include a section listing trending apps, fast download feature, and information on whether an application will make use of your personal data, or if it includes in-app purchasing.
Note that this preview is only available for S40 touch-and-type devices:
You should not attempt to install the Nokia Store app unless you are using one of these devices. Nokia Store is an interesting sneak preview of how the store will look in future. It's worth trying, but it's not a full, stable release.