The online retailer previously forced its video platform's users to leave the app and go to the Amazon website via a browser to make their purchases.
However, Prime users in the US, UK and Germany will now be able to access these features through the app itself.
A message altering users to the update has stared appearing this week, which reads: "Browse, rent, or buy new release movies, popular TV shows, and more - now within the app."
Previously, users of iOS or tVOS could only watch films or shows bought directly from Amazon's website - or on another advice like Fire TV or an Android phone.
Meanwhile, Apple is allowing Amazon to use its own payment system onthe app through iPhones, iPads, iPod Touches and Apple TVs.
Although the company usually charges 30% commission for in-app purchases - and requires apps to use the firm's own payment system - they have waived this charge.