jStock is a cross-platform stocks viewer and alerts utility written in Java. It allows you to set up a list of stocks, your stocks portfolio for multiple stock markets the world over. Earlier it used to use the Yahoo Stocks as a feed, but since that feed stopped retrieving many stocks, jStock now fetches the feed from Google Finance.
jStock is available for Linux, Windows, Mac, Android, and other platforms. You can save your stocks list or portfolio to Google Drive and not miss a beat when you start up jStock on other devices. Only, for the Android platform, you need to make a small payment to the developers to enable jStock as a service on the Android phone, else it only provides alerts while the jStock app is running on your phone.