This is a simple link shortener that can be activated from many places in Android. You can long press on the browser's URL bar and select Share, or select Share from the browser menu. It also works with the YouTube app and others. When it is done shortening the link, it is copied to the clipboard. You can select from is.gd or bit.ly. Bit.ly has account support through their API.
I've tried to keep this app very simple, to match its very simple purpose. You can download the app and it will "just work" with is.gd. If you'd like to change what shortening service it uses, simply open the Link Shrink icon from the launcher.
Link Shrink is licensed under the Apache license. Source code and issue tracker available at http://code.jakebasile.com/link-shrink/.