You get a small amount of free cash and unlock the Check In Card by doing so from the home page each day. It doesn't let you check in unless you enable notifications, using this as a way to ask for permissions.

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Pinduoduo (拼多多)

Sharing experience
App Store Screenshots
Card Gamification: Function Cards
Card Gamification: Behaviour Cards
Numbers
Top level navigation tabs
Product screen: Sections
Card Gamification: Category Cards
Card Gamification: Overview
Categories
New user experience and onboarding
Mini app in WeChat
Profile and more tab
Home page elements
Product screen: Overview
Checkout experience

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Gamification

Card Gamification: Category Cards
Gamification: Streak, Lives and Gems
Redeeming reward
Gamification and badges