It really depends on what sort of app you’re trying to write. If you just want simple database read/writes then something like Firebase or Pouch would probably be a great choice. I can’t speak to Pouch as much but I’m pretty familiar with Firebase and have written a couple apps with it.
Essentially firebase is a JSON database and a light server layer built in. You can read from/write to the database easily and as long as you don’t need to do lots of data processing or heavy backend logic it’s really easy and requires no backend coding. They also fairly recently introduce cloud functions which actually let you write bits of server-side logic more or less. Another nice thing about firebase in particular is that it comes with easy plug and play authentication support with a variety of providers (email/password, google, facebook, twitter, etc) and some other features, many of which are geared more towards mobile. There’s an ember addon for it too, so getting started is pretty easy.
So yeah if the app you have in mind is pretty straightforward read/write logic and you don’t need to lots of heavy processing or server-side logic I’d recommend looking into both to see which meets your needs. Firebase is fully managed, and the new database (firestore) scales automatically, but it costs money once you get to a certain volume. I believe Pouch is more of a self hosted server.