You should be able to use it with mission planner 2 on your Mac system. But could you please give me some more details on what the actual problem is? Have you installed the latest firmware. When you plug it in via USB do you see and LED's flashing on the APM board?
However depending what version of OSX you are using you might need to manually install the drivers to connect to your APM board, as this is a common issue.
Installing FTDI drivers for APM on your MAC
Once you have downloaded mission planner 2, you should open the file location and inside you will see the FTDIUSB serial driver .dmg file which you need to install. Inside the .dmg file you will see two more files. Open the file with 10_4_10_5_10_6_10_7 by holding the command key before clicking to say open.
You might get a message saying the driver is for !)_7, but its the correct one to use for all OSX versions up to 10.10.
Follow the FTDI setup wizard and once installed you should be able to connect to your APM board.