When you reset or wipe your Windows Phone 7, you might be knowing that all personal files will be deleted which includes your apps, pictures, videos etc. Even though you can easily sync pictures and videos from your PC using Zune, apps are not possible. You need to manually reinstall all the apps one by one on WP7. The same is the case when you buy a new WP7 after you have used one previously. In case you have been in such situations, the Reinstaller app for WP7 should be helpful. Reinstaller can help by presenting a list of all the apps that are associated with your Live account, and allow you to install all or just some of them.
When you click connect, you need to log in to your Windows Phone account and once authorized, the app shows the list of all apps available in your account. Then the app scans for all the installed apps from your account. You can select the apps which you want to reinstall on your device.
The app is pretty useful when you have lots of apps installed on your phone and you had to do a reset for some reasons.