Browse Through Posts Category wise, Categories, Pages.
API Plugin : https://wordpress.org/support/plugin/json-rest-api
You will need to install above plugin. Without it your app will not connect with your wordpress site.
Push Notification Plugin:
For this we have used Paid plugin so its optional to have it.
We have integrated below plugin from Codecanyon.
Note: We have not included plugin with this source code. You can use other plugin as well. You will need minor changes for the same.