There is a single PWM output pin that you can use to control a Piezo or a vibrating motor. The datasheet is a little unclear on how to use it in 'PWM' mode where you have full frequency and duty cycle control. In the mode we're using it, you can set the frequency from 1-2000 Hz and it will have 50% duty cycle. The PWM pin is the straight-from-the-module output, 2.8Vpp. The Buzzer pins have a PNP driver, so you can use it with a motor buzzer and power from the lipoly battery.
PWM Buzzer is available on the FONA800 and 808 Breakouts and Shields