Thanks for the answer, after reading it i took another look at the doc and now i am thinking a push to app notification could do the job with a simpler implementation.
On first login for a new user a user scope bucket is created and the user is subscribed to the bucked and created a object in the bucket using the device ID as the object ID.
Then each time the user login (or even saves data) on a device an update is made to the above item. Thus triggering a push to all devices.
From my understand this kind of push is not able to be customised but will contain the object ID of the object that triggered the push, by using the device ID as the object ID i will now be able to check the Object ID against the device ID when receiving the MSG and simply ignore it if it was sent from the same device.
Could this approach work or am i missing something??