Are we allowed to use app names on stories

You’re allowed to mention a trademarked name/product as long as it doesn’t drive the plotline and isn’t an advertisement, and you probably wouldn’t be allowed to upload the logo.

Fine

1: “What are you doing?”
2: “Just scrolling through Tinder.”
1: “Find anything promising?”
2: “Not today, it seems. Let’s go to the club instead!”

Not fine

1: “Where did you guys meet?”
2: “We met on Tinder! Tinder is such a great platform that lets you meet blablablabla…”

OR

A story told through phonetext format about one person’s dating adventures and misadventures on Tinder.

Those rules aren’t excessively complex, but most people avoid having to toe the line by just making up imaginary brands.