Zotero for iOS is the best way to work with your Zotero library on an iPad or iPhone.
Zotero for iOS lets you work with your Zotero data no matter where you are:
Sync your personal and group libraries
View and edit item details
Organize items into collections
Generate citations and bibliographies in any of 10,000+ citation styles (APA, Chicago, MLA, etc.)
Take notes on your research
Read PDFs and add highlight, note, image, and ink annotations
Easily save items and PDFs from the web to Zotero via the Share button in Safari or other apps (other browsers, Twitter, etc.)
Quickly add physical books and articles to your Zotero library by scanning book barcodes or article DOIs with your iPhone or iPad camera
Avoid straining your eyes with full Dark Mode support, including while reading PDFs
Back on your computer, you can add PDF annotations you've made on your iPad or iPhone to Zotero notes and insert those notes into your word processor document with active Zotero citations or export them to Markdown.
Please post to the Zotero Forums with any bug reports or feature requests. Be sure to mention “iOS”, “iPad”, or “iPhone” in your thread title.
Get Zotero for iOS on the App Store