You may have seen earlier this month that Google started testing a few new sale features on the Play Store. Select developers were able to set sale prices that showed up on the purchase button, and (finally) paid listings could be temporarily free. Now, that functionality is official. There’s a support page with all the relevant details developers can check out.
There are a few important things to know before you go setting apps to free all willy-nilly.
Google makes Play Store sales (including free offers) for paid apps and games official was written by the awesome team at Android Police.