A two-panel file manager in the spirit of the old desktop commanders. Two folders side by side, function keys at the bottom: F5 copies to the other panel, F6 moves, F7 makes a folder. Works with iPhone storage, iCloud Drive, USB drives and SFTP, FTP or WebDAV servers. ZIP, select by mask, compare folders, find files, tabs, three themes. On iPhone Duo unfolded like a book, each screen holds one panel. Free, no ads, no account, no data collected.