I want Yahoo Messenger like App & website.

I want a mobile app in modern language in which 1 app works in both Android & iOS e.g. React Native.
The App functionality will be just like YAHOO MESSENGER. For detailed study please visit following videos.
https://www.youtube.com/watch?v=qXRzBPtXuI8
https://www.youtube.com/watch?v=Vh0z94_fs1Q
Please can chat with individuals, Creating Groups, & in the Rooms.

-There will be text, Voice & Video chat option as well while chatting with individuals & group chats..
-There will be text & Voice chat available in Rooms (Mean no Video Chats in rooms).

Note:
- Please study about this as much as possible before applying.