08-06-2009 11:06 PM
The majority of apps are free to download and use. It all depends on the app. Some GPS apps that you have to pay for such as TeleNav are a monthy charge. Some like Beejive are a one time charge.
Now that's not taking into account the data usage charges. If you have a BlackBerry data plan with unlimited data then you're safe. However some data plans are capped (i.e. 500MB of data usage each month).