This feature-packed fan HAT for the Raspberry Pi includes a PWM programmable fan along with a 0.91" OLED screen for displaying your Raspberry Pi's temperature (or anything else you'd like to display!).
The HAT also includes a heatsink set, 16 PWM outputs for controlling other PWM devices and handy pin breakouts. The product Wiki includes example code.
PCA9685 PWM driver as the fan controller, powerful driving capability, auto PWM adjustment
0.91" OLED, 128x32 pixels, displays board temperature or other user-defined content in real-time
PWM controlled fan, up to 8000rpm speed bringing strong airflow