I'll revisit the idea of indexing tags after the android app is done (which is top priority now).
if you're looking at the android app - I tried it on Android 4.2 and, when set into vibrate mode, receiving a new transaction now causes a SecurityException:
java.lang.SecurityException: Requires VIBRATE permission
at android.os.Parcel.readException(Parcel.java:1425)
at android.os.Parcel.readException(Parcel.java:1379)
at android.app.INotificationManager$Stub$Proxy.enqueueNotificationWithTag(INotificationManager.java:228)
at android.app.NotificationManager.notify(NotificationManager.java:132)
at android.app.NotificationManager.notify(NotificationManager.java:108)
at piuk.blockchain.android.BlockchainService.notifyCoinsReceived(BlockchainService.java:256)
...
so sounds like you just need to add VIBRATE to the manifest...
Cheers
Will