I have made an exception to my "no Adobe" image processing boycott. When Adobe adopted their "let's charge rent forever" gouge for Lightroom I started using other RAW developers particularly RawTherapee. Most Adobe products are overpriced and overrated but their mobile apps may be an exception. The iPhone app Photoshop Express is free. Of course, it nags you to buy the expensive stuff and it probably spies on you like many phone apps but it is fun and enables basic photo editing on your phone.