While FreeM is mostly designed to work with BlinkMs and MinMs, it can be made to work with MaxMs. FreeM cannot supply the power that MaxMs need (250mA and FreeM can only supply up to 100mA), but there are other ways. One way to do it is to power the FreeM from the MaxM's built-in 5V power supply. To do this, get a MaxM, a FreeM, a small scrap of wire, and a 12VDC power supply.
Remove the "pwrsel" jumper and wrap the small piece of wire around all three pins of the "pwrsel" jumper. Then plug the FreeM into the bottom of the MaxM and plug in the 12VDC power supply to the MaxM.
The MaxM will power the FreeM and the FreeM will control the MaxM.
You can also now control other LED clusters like flexible RGB LED tape.