The PlayStation App will be free on iOS and Android, Sony has confirmed, and you will be able to start remote downloads on your PlayStation 4 via the app.
Sony Worldwide Studios Boss Shuhei Yoshida confirmed that players will be able to make purchases on their phones and then remotely start downloading them on their PlayStation 4. The app also allows players to send and receive text / voice messages to players on PlayStation 4 and even send multiplayer invites.
As well as what’s listed above, the app lets players view statistics, videos, activity feeds, and will also act as a second screen for certain games, such as Knack and Watch Dogs.
Source: PS Blog