THE PABLO DOT LIFE - The Life of Pablo artwork generator™
Photopea - Online photo editor, which can work with PSD, XCF and Sketch files (Photoshop, Gimp and Sketch App).
Coverify - Create your own custom cover art for Spotify playlists.
Replace Cover - Create beautiful cover art for your Spotify playlists
Podcast Cover Art - Discover the world’s best podcast cover art
Headers.me - Create social cover images that get you followers