Photo Editing App

For cropping even the Preview.app will suffice, that comes for free with every Mac, if you do not want to import the photos to the Photos.app.

What kind of edits do you need to do? Do just want to enhance photos or do you also need to do graphics compositing, like copy and paste objects between photos?

Food for thought: cropping with Preview will alter the image file you're cropping permanently. If you use Photos to crop an image you can always "Revert to Original" to get back to the original image.

Bottom line: if you use Preview work on a copy of the original image file if you want to preserve the original for later use.