Transferring application data between devices

1. A computer-implemented method, comprising:

causing, using a first component on a first device, the first device to establish a wireless connection with a second device, wherein the wireless connection is a connection that is separate from an Internet connection, and wherein the first device is not communicating with the second device via the Internet connection;

receiving, from a second component on the second device, data specifying one or more applications that are installed on the second device and supported by the second component, each of the applications being separate from the second component and the first component;

determining, by the first component, that a first application installed on the first device corresponds to one of the one or more applications installed on the second device, wherein the first application is separate from the first component and has first application data to be shared;

receiving, by the first component, the first application data from the first application; receiving, by the first component, an indication that a user of the second device has approved a data transfer; and

causing, by the first component, the first device to send the first application data from the first application installed on the first device to the second component on the second device using the wireless connection.

2. The method of claim 1 , further comprising:

determining, by the first component, that a second application installed on the first device corresponds to a second application of the one or more applications installed on the second device, the second application being different from the first application;

receiving, by the first component, second application data from the second application; and

causing, by the first component, the first device to send the second application data to the second device using the wireless connection.

3. The method of claim 1 , further comprising:

causing, by the first component, the first device to broadcast wireless connection availability; and

receiving a wireless connection request from the second device, wherein the first component causes the first device to establish the wireless connection with the second device in response to receiving the wireless connection request from the second device.

4. The method of claim 3 , wherein causing the first device to broadcast wireless connection availability comprises:

causing a speaker of the first device to emit an audio sample that specifies wireless connection data.

5. The method of claim 4 , wherein the wireless connection data comprises:

a service set identifier (SSID) for a wireless component of the first device; a password for connecting to the wireless component; and

data identifying the first application.

6. The method of claim 4 , wherein the wireless connection data comprises:

a short range communication identifier for short range communication compliant component of the first device; and

data identifying the first application.

7. The method of claim 4 , wherein the wireless connection data comprises a public key for encrypting communications between the first device and the second device.

8. The method of claim 1 , wherein:

the first application data is received by the first component through a first communications socket between the first application and the first component; and

the first application data includes an identifier of the first application.

9. The method of claim 3 , wherein the first component causes the first device to broadcast the wireless connection availability in response to receiving a first gesture input;

the wireless connection request includes a second gesture input; and

the first component causes the first device to establish the wireless connection with the second device only in response to determining that the second gesture input matches the first gesture input.

10. The method of claim 9 , wherein:

the first device includes one or more physical sensors for sensing physical motion of the first device; and

the first gesture input corresponds to a physical gesture interpreted by the one or more physical sensors.

11. The method of claim 9 , wherein:

the first device includes one or more touch sensors for sensing tactile input on a touch-sensitive screen; and

the first gesture input corresponds to a pattern interpreted by the one or more touch sensors.

12. The method of claim 1 , wherein the corresponding application installed on the second device and the first application installed on the first device are instances of a same application.

13. The method of claim 1 , wherein the first application data is received by the corresponding application installed on installed on the second device.

14. The method of claim 1 , wherein the first application data from the first application installed on the first device is more up-to-date than second application data of the corresponding application installed on the second device if the second application data exists on the second device.

15. The method of claim 1 , further comprising:

precluding, by the first component, the first device from sending to the second device, using the wireless connection, local data stored on the first device.

16. A system, comprising:

one or more data processing apparatus; and

a data storage device storing instructions that, when executed by the one or more data processing apparatus, cause the one or more data processing apparatus to perform operations comprising:

causing, using a first component on a first device, the first device to establish a wireless connection with a second device, wherein the wireless connection is a connection that is separate from an Internet connection, and wherein the first device is not communicating with the second device via the Internet connection;

receiving, from a second component on the second device, data specifying one or more applications that are installed on the second device and supported by the second component, each of the applications being separate from the second component and the first component;

determining, by the first component, that a first application installed on the first device corresponds to one of the one or more applications installed on the second device, wherein the first application is separate from the first component and has first application data to be shared;

receiving, by the first component, the first application data from the first application; receiving, by the first component, an indication that a user of the second device has approved a data transfer; and

causing, by the first component, the first device to send the first application data from the first application installed on the first device to the second component on the second device using the wireless connection.

17. The system of claim 16 , wherein the operations further comprise:

causing, by the first component, the first device to broadcast wireless connection availability; and

receiving a wireless connection request from the second device; and

wherein the first component causes the first device to establish the wireless connection with the second device in response to receiving the wireless connection request from the second device.

18. The system of claim 17 , wherein causing the first device to broadcast wireless connection availability comprises:

causing a speaker of the first device to emit an audio sample that specifies wireless connection data.

19. The system of claim 18 , wherein the wireless connection data comprises a public key for encrypting communications between the first device and the second device.

20. A computer readable storage medium storing instructions that, when executed by one or more data processing apparatus, cause the one or more data processing apparatus to perform operations comprising:

causing, using a first component on a first device, the first device to establish a wireless connection with a second device, wherein the wireless connection is a connection that is separate from an Internet connection, and wherein the first device is not communicating with the second device via the Internet connection;

receiving, from a second component on the second device, data specifying one or more applications that are installed on the second device and supported by the second component, each of the applications being separate from the second component and the first component;

determining, by the first component, that a first application installed on the first device corresponds to one of the one or more applications installed on the second device, wherein the first application is separate from the first component and has first application data to be shared;

receiving, by the first component, the first application data from the first application; receiving, by the first component, an indication that a user of the second device has approved a data transfer; and

causing, by the first component, the first device to send the first application data from the first application installed on the first device to the second component on the second device using the wireless connection.