Best general-purpose communication app
Facebook's free WhatsApp does almost everything, and because it's so popular, chances are your friends are on it too. The last piece, video calling, is currently in beta testing.
Best daily weather app
Dark Sky's predictive weather notifications will keep the rain and snow from catching you off guard.
Best photo app
For mashups, filters, shape overlays, collages, frames -- pretty much everything you can do with a photo -- PicsArt delivers in an easy-to-use and attractive app. Plus, it supports raw photos and you don't need the in-app buys.
Best music app
For general music listening and discovery, Spotify makes it easy to find new music and connect with your friends by way of themed playlists for genres, moods, and weekly highlights of new tunes picked just for you.