Hotpot is a Photoshop alternative for developers, entrepreneurs, and marketers.
Use this free service to resize images for iOS, macOS, Android, Chrome, and other platforms.
For instance, iOS requires retina images at 2x and 3x resolution while Android mandates support for 4x (xxxhdpi), 3x (xxhdpi), 2x (xhdpi), 1.5x (hdpi), 1x (mdpi), and 0.75x (ldpi) drawables. (Thanks iOS and Android overlords! Supporting multiple devices and battling thousands of other talented developers is definitely not enough of a challenge.)