> I love Slopes and its lone developer deserves all the praise, and yet a week ago I've received an unwarranted ad for the paid subscription disguised as a notification... Not cool.

You just need to notify Apple that a particular App in the store violates their ToS.

I've done this before, and in a matter of a few days, the App is removed from the store, and the other apps of that dev are scanned for ToS violations. Then all other apps of those devs are removed from the store, and then the dev is banned from the store. If the dev wants to regain anything back, then they will have to go through a very expensive multi-month long process to achieve that.

Apple does not mess around, so I would reach to the dev of an App you like and use personally first, because the moment you notify Apple it will rain Hellfire.