For some reason both the monitor and settings pane slide out on the right side. I cannot grab the resize box to move it to the other side. This means I have to close the monitor pane to see/change the settings.

The compass heading changes, sometimes wildly, at very low speeds. This might be minimised by averaging the heading over time, increasing the time interval the slower the speed. At 0-0.2 mph (my current standing still reading) where the position hasn't changed in a while, maybe don't display the compass, grey it out, or do something to note that it isn't very reliable.

Otherwise this is very good. I downloaded it to test my USB GPS (Rayming TN-200) before Route 66 arrived, and it meets and exceeds my expectations. This should be included on all Mac compatible GPS CD-ROMs.