Sometimes you have to share different links on facebook or twitter. Many times the links (URLs) are so big that they look bad, so links need to be shortened. Any link (URL) is short / short for the website and address of Android Apps.
Google Shorter website
http://goo.gl
Android Apps
https://play.google.com/store/apps/details?id=com.mattiamaestrini.urlshortener
Bitly Shorter website
http://bit.ly
Android Apps
http://play.google.com/store/apps/details?id=com.bitly.app
Tiny URL short
http://tinyurl.com/
All Shorter Together One Android Apps
http://play.google.com/store/apps/details?id=de.keineantwort.android.urlshortener