With the wild range in prices for silver it’s wonderful to have a new app for the iPhone / iPad called Silver Tracker. It has useful historical charts and currency conversions, but the best feature is the price monitor. In an icon badge it shows the current price of silver (you don’t have to open the app to see the current price), but you can also set it to notify you if the price dips below a price you set. I chose $18 (I’m an optimist) so that if it ever gets below that I can shoot a stock-up order to my vendor.
It only requires iOS3 so it works with older phones and it’s only $1.99. They also have the same type of app for gold.
Get it in the App Store.