No idea if it will happen but I'd love a Steam App store on iOS. If I buy an game that runs on Mac/PC/Android/iOS I'd love to be able to buy it once and play it

No idea if it will happen but I'd love a Steam App store on iOS. If I buy an game that runs on Mac/PC/Android/iOS I'd love to be able to buy it once and play it everywhere. I can do that Mac/PC/Linux at the moment, would be nice to add iOS and Android as well. And, even if they aren't the same game it would nice if buying a game on steam unlocked some companion app on my phone via a Steam iOS/Android store.