Not really. They don't have a use because regular money serves the market just fine. WhatsApp supposedly collects $1 per year (plus more for "extras") from hundreds of millions of users via mobile payments, app stores, or whatever. Likewise countless mobile F2P games that collect lots of money.

There just isn't a big mass market hole when it comes to payment services that crypto can jump right in and hope to fill.

If you do have a great idea for a social app, a game, or whatever, you should just launch it using app store payments and make bank. From a business perspective, crypto is a waste of your time, and probably trying to push it into the app will just destroy value, not add it.