Pushbullet is a cross-platform application that aims to connect multiple devices to create a shared user experience: with it you can share your phone’s notifications to your computers, share files/links/notes between devices, and answer messages on your phone from your computer.
Developed by a six-person startup, it’s been described as a life-changing application. It recently received $1.5 million in seed funding, and it’s expanding rapidly: at the moment is available both on desktop (as a browser extension or application) and mobile.
I tried using it with an Android smartphone and a Macbook: in this case it’s especially useful, because otherwise the communication between the two devices would be quite limited.