Hi Sourabh,
If we can talk about that how we can mantain the order and track of all notification ? There is different ways to mainain : -
1. You can save your notification on Cloud using our Storage Service with time and addtional data of user.
2. You can save in local storage.
Also you can track of all the messages which is not opened by the user by using App42 Event API Click the url and see Doing Push Analytics.