Notification Sound
You can change the default notification sound for the apps.
The following procedure can be used for all the 3apps.
NOTE: Your notification sound should not be longer than 15seconds
Android Notification Sound
Navigate to the following folder: android > app > src > main > res > raw
There is a alert.mp3
You can change the file to your own custom sound, but must be named alert.mp3

iOS Notification Sound
Navigate to the ios folder
There is a alert.aiff
You can change the file to your own custom sound, but must be named alert.aiff

VENDOR APP
For the vendor app, from version 1.4.6, there is alert_new.mp3 and alert_new.aiff in android and ios folder respectively. There is the notification sound for Newly placed order with the vendor, so vendor can differentiate new order alert from other notifications