You can get your SHA-1 fingerprint from your keystore.
$> keytool -v -list -keystore <keystore path>
For example:
$> keytool -v -list -keystore ~/.android/debug.keystore
For a meteor application, you need to use this keystore:
$ keytool -list -v -keystore ~/.meteor/android_bundle/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android