You can see old notifications on an Android that you've previously cleared via the device's Notification Log, which is accessible in Developer Mode.

How to add custom notification sounds and ringtones for contacts When your calls come through, you can instantly recognize who they are based on the new sound or ringtone you've set for your contact.

Deleted WhatsApp messages are reportedly saved in an Android smartphone’s notification log, which can easily be accessed using a third party app. The method only works on devices running on ...