Amazon starts rolling out Amazon Offers update to remove lockscreen ads and offers on Prime Exclusive phones. It seems that the decision is due to the recent finding of security flaw on these phones caused by the lockscreen ads. As the roll out go on in phases, it will take some days to get on all Prime exclusive phones. However, if you cannot wait the update, Amazon Offers APK is now available for download that you can sideload.
As you may know, Amazon offers Android handsets at discount price for Prime Members, but to get this deal, Amazon will provide you with lock screen and notification ads on the handset. Also, these devices come with a bunch of Amazon bloatware apps. Now, the company decided to remove ads and offers from these devices.
The security flaw is like this: The lockscreen ads allow people to unlock the phone without knowing the PIN, Pattern or Password. The issue was actually happened if on-body detection is turned on. However, with this update any ads or offers will not be displayed on the lockscreen.
Thanks to the XDA Forums user DarkPhoenix7878 for the Amazon Offers APK (extracted from the update), you can sideload the app to disable ads on your phone.
Download the Amazon Offers APK from here that you can install on any Prime Exclusive phone to disable lockscreen ads. According to the source, you need to wipe cache by booting into recovery mode before disabling ads and offers (Source 1, 2)