What is SHA1 fingerprint?

It is a standard for the implementation of a 'secure hash algorithm' - a one-way cryptographic function that can be used to act as a 'signature' of a sequence of bytes. It is very unlikely that 2 different byte sequences would produce the same value (though not impossible)

http://en.wikipedia.org/wiki/SHA-1

Note that there are other, more robust standards out there these days e.g. SHA256 and beyond.

They are asking for the SHA1 fingerprint on your keystore file (You sign your apps using this before you can push them to google play)

you can get your key by doing this

keytool -exportcert -alias your-key-name -keystore /path/to/your/keystore/file -list -v

you can use your keystore file from another computer just put it on a USB stick or email it to yourself (Make sure to keep it private !IMPORTANT!) and point your IDE to the file

If you are using Eclipse IDE, the easiest way to get the SHA1 fingerprint for your app:

• click on your app project, in project explorer (on the left)
• from the top menu, click Window -> Preferences
• in the Preferences window, on the left, expand Android and click on Build

You should see the following information:

• default debug keystore path
• MD5 fingerprint
• SHA1 fingerprint

You can also add other keystore file (for example, production keystore), and the values for that keystore will be shown also.