I have never seen a shopping mall with a sex shop. Maybe lingerie or some novelty items at a Spencer’s, but I doubt mall operators would want to deal with people complaining about their kids walking by a store selling pornography and sex toys.
They usually end up in undesirable locations or in rundown strip malls.
I go past a mall with a dildo shop inside it on my current walking commute to work.
I saw another one of the same chain in the main train station of… I think it was Hannover? I was travelling a lot by InterRail and the places are blurring together.
Zürich has (or had) a sex shop with the wares clearly visible from the outside in the expensive bit of the city centre.
Cambridge (UK) has an Ann Summers in its main shopping centre. Thinking of the UK, I’ve seen vibrating cock rings openly stocked in Tesco, which is the largest supermarket chain in the UK.
Attitudes to such topics are surprisingly flexible.
I think most of the comments here are US-centric, which also happens to be where the app stores are mostly implemented, so they come with the same source values.
They usually end up in undesirable locations or in rundown strip malls.