If you have enabled free in-app credits for an app, these are issued only to new installations of your app. Free credits are limited once per device (even if "Device Recovery" is disabled) since our API will still recognize their device if an end-user re-installs an app. However, if the same end-user installs your app on multiple devices, they will receive multiple allocations of free credits - unfortunately there is no way to detect when the same user is using different License Keys on different devices.