While iOS has had its own file manager for a while now, it's relatively limited. FileBowser gives you 'desktop capabilities', a Windows Explorer for your iPhone or iPad.
Managing files isn't something iOS is very good at out of the box. Thanks to the Files app, a few things have already been improved, but it still remains to be done. By installing the FileBrowser app (and we advise you to immediately purchase the Biz version, more about that later) you get much more extensive options in terms of file management; including access to folders and files on, for example, your NAS or in other shared network shares. But FTP and more are also in the list of features. Furthermore, it is also a viewer for a variety of file formats - including images and sound - while PDFs can be annotated. There is a free limited version of the app available, the regular version with the blue icon costs €6.99 and the business version €11.99. This latest version is recommended if you regularly want to access, edit, move, copy, etc. larger files from shared folders. Only the Biz version supports smb3, which provides a much higher throughput than the maximum available SMB2 in the standard version. It makes transferring files to and from your iPhone or iPad a lot more user-friendly, in our experience. Make sure that when you add a new share (this can be done via the + in the main window), you under Advanced settings behind SMB versionVersion 3 onset (or possibly Automatically). Only then can you be sure that the maximum throughput is always achieved.
Just like Finder or File Explorer
Otherwise, FileBrowser works just like File Explorer in Windows or Finder under macOS. You can grab and drag files and folders. It is also possible, for example, to transfer photos and videos from the Photo Library on your device to an external folder. To do that, tap photo library and then (for example) on Film role to see all your photos and videos at a glance. To copy a single photo or video clip, tap the button with the three vertical dots after the file name. Then tap copy, then browse to the destination folder on your NAS and tap Paste 1 file here. Or select multiple files at once by pressing Select tap, select the files, and then tap copy to tap. Browse to the destination folder and tap Paste 4 files here.
Cloud services
Filebrowser - and in particular the Biz version - also offers the possibility to link to various cloud drives. Think of OneDrive, SharePoint, Google Drive and more. This creates a very versatile whole that provides iOS with something very basic: desktop-quality file management.