Affinity Photo

Serif’s plucky Photoshop rival has already proved its worth as a standalone image editor. However, it’s also a first-class add-on for Photos, greatly extending the built-in features.

Under Photos in System Preferences’ Extensions pane, you can click Photos, and pick which of six tools to make available: Develop, Liquify, Monochrome, Miniature, Haze Removal and Retouch. Combining Affinity Photo’s best image editing tools with Photos’ organisation tools does much to fill the gap left by Aperture’s demise, making a capable and affordable workflow if you don’t want Adobe’s Lightroom.