Chrome extension which simply shows the current price of bitcoin on the badge icon. Supports multiple currencies and exchanges.
https://chrome.google.com/webstore/detail/btc-ticker/bmcdgjdhkiafkocajnobfhipmjolceeg
If you like this, you can donate here: BTC: 3Anxg3D5iSuYasWCKmfs7Dj7S2Eq5Vhbia