Whatsapp is a messaging app thats only been using for sending messages, videos, photos to my friends for the last 5 years. one of the main reasons being love it is the backup process. we can back up our data and chats videos, photos with a single click.
also, the chats are secure that cant be tracked by another one. although. it has a bad feature that I want to be fixed. if someone registered their phone number on WhatsApp and after some time if he removes his sim from the phone then the WhatsApp will run without any sim. and this feature is very dangerous.
it also has some restrictions like we cant send one message to more then 5 peoples at a single time and the image quality will drop if we send via whatsapp. and we cant send a long video to anyone.