If you have an ipad (and possibly apple pencil): Paper (Freemium), Procreate, which is paid (and similar, like ibis paint, which is freemium), Goodnotes, freemium (and similar, like freenotes or notes+, which should be both free)
Apple devices: Freeform (free), Ibis Paint
Any device: Canva (freemium), shuffle by pinterest (i never tried it but i think it works, not paid but i'm not sure if it's freemium or free) and i think 17v28 too (i think freemium)