Shortcuts

Shortcuts helps you interact quickly with your WhatsApp contacts. All you have to do is choose the people you interact with the most and their icon will appear over any app you're currently using, so you can always reach this person's WhatsApp chat conversation quickly.

Also, you can customize contact icons by selecting a nice avatar or upload a photo from your device.
You can use beautiful bubbles filters in a variety of colors, add text to your icon etc.