I am one of the frustrated apple users who wish Photos had not replaced Aperture. However with El Capitan, plug ins or EXTENSIONS have been added. This is great news. Affinity repair brushes are great whereas Apple's ones are rubbish so I want to be able to use Affinity's as a plug in/ extension. I bought Affinity. I downloaded the beta. I opened both the purchased copy and the beta. I restarted my Mac and opened both copies again, but Affinity is not there as an extension in the Photos programme. I hit the more button but it's not in the Extensions box to add. I had no problem making Pixelmater available as an extension except that it only offers the distortion tool. Can anyone suggest what I may be doing wrong?