The legislation, a sweeping amendment to Arizona's existing HB2005,  prevents app store operators from forcing a developer based in the state to use a preferred payment system, putting up a significant roadblock to Apple and Google's ability to collect commissions on in-app purchases and app sales.

It will now head to the state senate, where it must pass before its sent to Arizona Gov. Doug Ducey so you can expect Apple and Google's lobbying teams throwing a lot of money at senators in the next few weeks.

The amendment specifically prohibits stores exceeding one million downloads from requiring "a developer that is domiciled in this state to use a particular in-application payments system as the exclusive mode of accretive payments from a user".

It covers users living in Arizona from having to pay for apps using exclusive payment systems. The bill specifically exempts game consoles "and other special-purpose devices that are connected to the internet", and it also bars companies like Apple and Google from retaliating against developers who choose to use third party payment systems.