[Johnythree]

Most cheap FM receivers definitely use a PLL to detect FM. Giving automatic tuning is just a side benifit.

[jhallenworld]

Do you mean AFT (automatic fine tuning)? This has nothing to do with a PLL-based demodulator. Older receivers with ratio detectors or discriminators also had AFT- there is a low frequency feedback path from the demodulator to the local oscillator to make this work.