This wonderful fully-featured compass uses the built-in GPS in the smartphone to show your line of travel, speed, latitude and longitude and where North is in relation to your heading on a variety of stunning backgrounds. To establish a line of travel, you MUST BE MOVING to use it!
Compass can now store locations called WayPoints and integrates those WayPoints with Google Maps and BlackBerry Maps!
A few words of explanation regarding Compass and how it works and behaves:
Compass is a GPS-based app like Google Maps or BB Maps. It needs access to the GPS location data on the phone and it uses that information to establish your 'heading'. As with all directional functions in Compass (and most GPS units, for that matter), this 'heading' is interpolated from REPEATED readings of your location. In other words, if you STOP MOVING, the BlackBerry has no way of knowing which way is "forward" and the arrow will likely start to spin around or not do anything at all.
Compass requests the location information from the GPS chip once per second (this is the shortest interval allowable) and if that information hasn't changed from the previous information it processed, it doesn't understand its direction.
How far you have to move before the GPS chip senses that it has moved from the previous lat/long is dependent on the number of satellites it is tracking and thus its accuracy but, in general, about 5 - 10 metres is pretty normal, though it can accurately show your heading and True North in as little change as 1 metre. Simply rotating the phone or setting it down on a table is not enough at all, for the reasons stated.
There is a tendency to compare it to the iPhone compass but the iPhone has something called a magnetometer in it. It's a hardware chip that your phone simply doesn't have. This is a SOFTWARE solution and is the best we can do for now... at least until BlackBerrys are manufactured with a magnetometer.