Affinity Photo is a direct competitor (same price range, similar feature set) and runs on both Windows and Mac: https://affinity.serif.com/en-us/photo/ https:/

Affinity Photo is a direct competitor (same price range, similar feature set) and runs on both Windows and Mac: https://affinity.serif.com/en-us/photo/ https://affinity.serif.com/en-us/photo/ Their UI's more Photoshop-style than Pixelmator Pro's, though.