WhatsClone an application that allow to have a real-time chat with friends (Like WhatsApp). You can send and share (images or videos or audio or pdf) ...etc. there is a database local to save your messages, so when user lost the internet connection he can write a message, the message will be saved on database local and once the other user come online the app will send your message directly.

Demo: https://codecanyon.net/item/whatsclone-with-socket/17553421