Apps
For a list of apps on different mobile devices see the Zotero for Mobile support page.
Collecting to Zotero on iOS
Using the Zotero app on iOS devices is most effective. After downloading the app, you can share sources located in a browser app using the "share" function. Depending on your browser, this may look a little different or be in a larger set of tools. Look for the icon that looks like a box with an arrow pointing upwards. Here is an example of what that looks like, though it can vary slightly from app to app: 