Alternate for Ionic push server


  I am using Ionic push notification service. As we know ionic is going to shutdown their services from JAN 31st, 2018. 

  Now we have three options

      1. One signal
      2. Amazon Pinpoint
      3. Firebase

  Amongst these three which one is better to use.

  I need your comments for these guys. Kindly help me out.

  **NOTE** : It has to support ionic 1 also.