Krita is a free and open-source painting program made by artists that want to see affordable art tools for everyone.
Krita can be used to create concept art, texture and matte painters, illustrations and comics.
Photopea is a free online image editor.
It supports PSD, XCF, Sketch, DD and CDR formats (Adobe Photoshop, GIMP, Sketch App, Adobe XD, CoreIDRAW)
You can create a new image or open image form your computer and export or save them in various formats such as PAD, JPG / PNG / SGV, WEBP, PDF, GIF, MP4, RAW, ICO, BMP, TIFF, TGA, EMF, PPM etc.
Photopea is available at photopea.com