In March 2022, an iOS app was released for Zotero, enabling users to easily access their Zotero libraries on an iPad or iPhone. You can find the app in the Apple Store.
There is currently not an official Android app for Zotero, but there are several third party apps that allow for limited mobile use of Zotero.
Please note: All screenshots were taken on an iPad running iPadOS 15.4.
Once you have installed the Zotero for iOS app on your device, you can use your Zotero.org username and password to sync the app to your web library. The Zotero for iOS app has the same basic format as the desktop version, albeit more streamlined and lacking some features, as the below screenshot shows.
In order to view and edit citation information for an item in the library, you will click on the icon to the right of the item title, which looks like the letter "i" in a circle. When you click on the title of an item, if there is a PDF attached, the PDF will open, and if there is no PDF, then you will be taken to the item's URL, if the Zotero entry includes one.
Note: PDFs linked through Zotfile and stored in a cloud storage system--e.g., Dropbox, iCloud, OneDrive--will not be able to be open in the iOS app. Only PDFs stored within the Zotero library or using WebDAV will be accessible in the app.
When you open a PDF within the Zotero for iOS app, you will be able to highlight, draw on, and add notes to the PDF. These annotations will be viewable in the PDFs in your desktop library as well, as long as you have updated your desktop app to Zotero 6 and have file syncing turned on in the desktop app.
There are fewer options for adding items to your library with the iOS version of Zotero compared to the full desktop version. You can add an item manually (click on the plus sign to the right of the search bar and then choose "New Item") or you can use the sharing function in Safari to send an item to your library.
While the Share button in Safari works fairly well for adding an article's information and PDF directly from the publisher's website to Zotero for iOS, it does not work as well if you try to share an item from a database, such as PubMed, to Zotero. If you use the Safari sharing function from an item's PubMed listing, only the citation information will be put into Zotero, and you will need to add the PDF separately.
If an article is in PubMed Central (PMC), then it is possible to add the reference information and PDF simultaneously without going to the publisher's website. When you are viewing an article in PMC, it usually defaults to the below HTML view. In order to send both the reference information and the PDF to the Zotero for iOS app, you need to click on the PubReader view.
From the PubReader view, you can then click on the Share button in the Safari toolbar and select Zotero from the options that appear. If Zotero is not listed as an option, click on "More."
If you add just a PDF to Zotero using the iOS app, the metadata will not be retrieved, and you will be left with just a PDF with no additional information in your library (see below image). The desktop version of Zotero can pull metadata from many PDFs, but this capability has not been added to the iOS app yet.
However, if you end up with a PDF with no citation information attached in your library, don't worry--you will not need to manually add all that information. The next time you open your library in the desktop version of Zotero, find that PDF, right click on it, and select "Retrieve Metadata for PDF." If the PDF is formatted correctly and has a DOI, then Zotero will be able to pull the metadata and populate all relevant fields.