I know companies wouldn't be able to put 14 year olds on their payroll. However, given the proliferation of devices and apps, what are the legal and ethical way

I know companies wouldn't be able to put 14 year olds on their payroll. However, given the proliferation of devices and apps, what are the legal and ethical ways of getting your pre-production app or device into the hands of users who otherwise cannot give consent or be hired?