Since the Google Play Store launched, Android app developers have been unable to give users access to paid applications for free. This has been a requested feature for many years, as app builders typically need the ability to allow certain users try their app, or access paid features within it, at no cost.
Google has finally given app creators the ability to hand out promo codes for their apps on the Google Play Store. Developers will be able to create up to 500 one-time use codes for either the purchase of an app, or an in-app purchase, with the 500 code limit resetting at the end of every quarter.
Promo codes are flexible, with expiration time lasting up to a year. These codes will be redeemable either via email or from within an app, depending on the developer. Codes will not be available for renewing subscription-based purchases, only apps themselves, or one-time in-app purchases.
[source]Google[/source]
