The wishlist allows you to vote for site features, I expect both your requests are already there, so go vote for them. I expect you will find heavy opposition to this both from the community and the GOG staff. GOG's security policy (as well as being secure) is to keep the minimum amount of personal data necessary. Once they store your card data, it makes them more of a target, and it makes a breach all the more serious. I see your point on this, it would probably result in more people actually taking advantage of sales when they're somewhere without easy access to a desktop. However as Fenixp said, it would be better to not go platform specific, and just make a mobile version of the site.