Have you decided to hide some Facebook applications [or friends or pages] which you now want to unhide or reinstall? The process to bring back those apps onto your News Feed is actually easy. Just follow the step-by-step guide below. It will only take you 30 seconds [or less] to complete the whole process. Here it goes!
➊ On your Facebook's News Feed, choose Top News instead of Most Recent feeds.
➋ Scroll down the page and click the Edit Options feaure.
➌ A Hidden From News Feed box will pop up. Click the Applications button and choose which app/apps you'd want to reinstall or unhide on your news feed wall. It's in alphabetical order so it's easy to mange.