Let me make a better example.
A Restaurant puts adverts in the local papers, and social media, We give away free food & Drink, and in their window they have BIG neon signs saying come in, free food & Drink here.
Everyone goes in and yes indeed, they are giving away free food.
Boiled white rice & water
All around the place inside are steaming piles of beautiful currys and other tempting foods.
They keep coming up to you wish price lists, telling you how amazing the food is that can go with your rice, also the wide range of amazing drinks.
The prices are low, for a little of this other amazing food, it smells great and looks great, and they keep guiding you over to see it.
Yes, they are giving everyone free food and drink.
But would this be really false advertising?
Everyone knows full well it's a cheap marketing gimmick to draw people to the store under the impression they are giving away more than just white rice and water.
I don't think such a food place should be able to run marketing campaigns saying come to out new place for all the free food and drink you want.
It's deliberately misleading. they know it, and we all know it.
Others here are saying it's fine, as they are doing what they promise in the adverts.
I just disagree.
I have seen signs for buffet's 7.99 (price example). You pay extra for the drink, that is typical in the US.
Your example is not a good one as "free food" is much more vague than a "free app". In fact I have never seen anything like that in any of the countries I have been to. With a free app, the app is indeed free.
On the other hand.
I also agree with the above poster, it's a ridiculous argument. As long as they let you know that the other food costs when you ask for it (as with in app purchases) there is really nothing wrong. In fact I know plenty of people that would be more than happy with free rice, it's a first world problem to complain about ANY free food.