Don’t use fast food apps, their only and sole purpose is to collect your data.
The McD app doesn’t run on Graphene because it can’t get info to sell off so it can fund the discounts you get from using the app.
That’s the economics of it. Your data gets sold at 100% value, you get discounts worth 60% of that value, they pocket the difference.
On another note, be careful of any loyalty program these days, even if it’s not digital. They use it to track exactly what you buy and at which location, e.g. grocery stores, and give you discounts in exchange. Sometimes it’s just for inventory and stock management, but some less scrupulous companies will sell off your consumer data for an extra buck, especially if you tied a name or address to your loyalty program membership.