The iPhone lets apps store files but those files exist only in the app that created them. For example, if you create a file in Excel, that file can’t be accessed from Google Sheets. As of iOS 11, users have the option to save files to the Files app and access them from other apps. This means that you can now download files on iOS if you have the right tool and it just so happens that Firefox for iOS is that perfect tool.
This is a new feature in Firefox so you need to update the browser to the latest version that’s available. Go to the download page, and download the file you need. You will see a progress bar at the bottom of the screen. Once the download completes, you can view it in the Files app.
Open the Files app, and tap ‘On my Phone’, and you will see a Firefox folder. Tap it and you’ll find a Downloads folder inside. Inside this folder, you will see all the files you downloaded via Firefox.
This might not seem like a big deal but you can move the files from your phone to iCloud via the Files app. Once you do that, you can open iCloud on your desktop, go to the Files app, and access the downloaded file from there.
Neither Firefox nor the Files app will let you view the files unless they’re common file types such as TXT or PNG. If you’ve downloaded a ZIP or RAR file, you won’t be able to extract it in Firefox or the Files app.
Files is Apple’s solution to a central storage area that all apps can access that isn’t the camera roll. It’s not going to change the operating system’s file structure so the app is a reasonable solution. It’s clumsy to use and moving files from on folder to another isn’t exactly intuitive. You can add additional cloud drive services such as Google Drive, Dropbox, and OneDrive which means if you don’t use iCloud, or you’ve run out of space on iCloud, you can use some of the other cloud drive services to save files to.
If you have a file editing app that can edit a file you downloaded, and that can also access files from the Files app you will be able to open and edit it. If you need to download a DOCX file, you can save it to the Files app via Firefox, and then open it from Microsoft Word.