how to play crazy house in app?

You have to use the website.

Isn't chess.com supposed to be the premier site for chess? 

And you can barely play any different formats in the app. 

Not very good is it. 

The website has more features. The app has a lot of things, mainly the core features, and isn't meant to replace the website. 

In the website how can people play crazyhouse or bughouse?

There are two places for Crazyhouse. In play you can create a custom game and change Standard to one of the available variants, including Crazyhouse and Bughouse.

You can also play Crazyhouse under Play > 4 Player & Variants

Guys Whats Better KID or KIA

Whats Better

What does that have to do with the topic? Nothing that I can see.

Better to start your own thread or search for an older thread than to randomly post in an unrelated thread.