This update from Apple will improve the functionality of this app. No new features are included.

1. Updated Synology's terms and conditions for EU data privacy compliance. 
2. Optimized the compatibility with iPhone X and iOS 11.
3. Terminated the support for the built-in PDF editor. Users can still use third-party apps (e.g., Adobe Acrobat Reader) to smoothly edit PDF files and save them to DS cloud.
4. Minor bug fixes.