Adobe Photoshop, GIMP, Krita, Paint.NET, Microsoft Paint, Photopea, Affinity Photo, Adobe Photoshop Elements, Photoscape, Pixelmator, Pixlr, Photo Editor, GraphicConverter, ToolWiz Photos, FotoFlexer, PicSay, TurboCollage, Picnik, Picozu, Photogene, Aviary Photo Editor, Movavi Photo Editor, PolyGen, Glimpse Image Editor, ImgPen, Image Edit PRO, CloneGram, XnRetro, Flare for Mac, Splashup, Photo Zoe, Beziercode, TIFFany, Stet.io are some alternatives to Acorn.