A few normally-paid Android games currently available for free on Google Play, though they all seem to still contain ads and/or microtransactions so I don’t know if the premium part is basically a scam. Comment if you can be bothered to investigate, I know I can’t!
Mobile games have a bad rep, but I’ve got to assume that we’re all adults who know how to block ads and ignore predatory game mechanics. Ultimately there are lots of people for whom a phone is their only way of playing games and they deserve freebies too, but I still want to make it clear that I don’t think that sort of thing should be the norm.