If you're not familiar with Pixelmator Pro, it's an affordable but powerful image editor that's just as useful for editing photos as it is illustrations. One of the highlights of the app is the fact that it can directly integrate with Apple's Photos app, allowing you to edit a photo and then seamless import back into your library. It's also a non-destructive editor, so undoing any edits is a breeze. The sale ends on October 29th.

Buy Pixelmator Pro on iTunes - $20