Which one should I pick for a new project?

I need more context to give you a meaningful recommendation. These are two completely different libraries solving different problems:

binarywang/wxjava — A Java SDK for WeChat backend development, supporting:

• WeChat Pay
• Official Accounts (公众号)
• Mini Programs (小程序)
• Enterprise WeChat (企业微信)
• Open Platform
• Video Accounts (视频号)

cymcsg/ultimaterecyclerview — An Android UI library providing:

• Enhanced RecyclerView with swipe-to-dismiss, animations, drag-drop
• Sticky headers
• Load-more functionality
• Quick adapter patterns
• Floating action buttons

Pick binarywang/wxjava if:

• You're building a Java backend that needs to integrate with WeChat services (payments, messaging, mini-app authentication, etc.)
• You need to handle WeChat OAuth, message callbacks, or payment processing

Pick cymcsg/ultimaterecyclerview if:

• You're building an Android mobile app
• You need an advanced RecyclerView with features like pull-to-refresh, load-more, or item animations

They solve completely orthogonal problems. What's your project type and primary need?

---

FOLLOW_UPS:

• Are you building a backend service or Android app?
• Do you need WeChat API integration on the server side?
• Are you looking for mobile UI components?