Redesign WhatsApp

Finally, after 2 weeks of hard work, I completed my very first UI/UX prototype. As a beginner its difficult to choose from where to start learning but after choosing any project(by yourself) or copying(of any professional artist) it made easy to learn basics. So I choose to redesign UI/UX of WhatsApp as per my thinking. Inspired from templates available on 'uplabs.com'

Here the most important thing which I added to my prototype is 'Scan to Add', that's my idea to simplify the process of saving/adding any contact with the help of Barcode.

What operations you can do in my prototype:
-tap 'Right-Arrow Button' to proceed in login, password and OTP page.
-on any chat, you can 'Swipe-Right' to Call and 'Swipe-Left' to Delete or Block any friend.
-to open chat, tap 'Minus'. Tap on the 'Paperclip' icon then on the 'Payment' icon to pay.
-tap on any friend's profile pic for more options and another tap on floating profile pic to zoom pic. Tap on the 'Info' icon to see 'About & Phone Number' of a friend.
-tap on profile pic which is at the uppermost left corner, then on the name 'Vinayak Thube' to open 'Profile' detail.

My Prototype file contains screenshots of:
-Login page
-Password page
-OTP page
-Home page
-User's 'About & Phone number' page
-Friend's 'About& Phone number' page
-Chat
-Calling
-Status
-Payment page

To test prototype online in browser click link: https://projects.invisionapp.com/prototype/ck0t44p62002vwt0130lsgrio/play

or if you are InVision user you can download this file and open it in InVision app. To download click link: https://drive.google.com/open?id=1766t8FsxjbmZdhYS1jc_gnFrKGzPhjPa

As a beginner, I would like you to recommend some suggestions which will help me to improve in the next prototype. 

"No matter how suggestions are, positive or negative, they are always one of the best teachers to teach what's wrong and right."