Share files between computer and iPhone
You can now share files between Windows PC and iPhone iPad over Wi-Fi using the Files app without third-party apps.
Mac
Connect to Mac File Sharing from iPhone iPad
How to connect to Mac file share from iPhone or iPad using the stock Files app?
Remotely access computer from iPhone or iPad
How to remotely access my computer from iPhone or iPad using VNC?
Calibre
Calibre is a free and open-source e-book management software for Windows, Mac and Linux that can organize, convert, and read e-books in various formats.
How to Connect to an FTP Server from iPhone?
Create FTP server on iPhone, connect to an FTP Server from iPhone.
Owlfiles File Manager
Owlfiles File Manager for Mac, iPhone, iPad. Access files on local storage, server, NAS and cloud storages. Transfer files from any location to another. Stream movies and music to your mobile or desktop device and even more.