To begin with, the interface has been overhauled to make better use of screen space and make filenames easier to read, while an ellipsis button next to each item brings up a new contextual options menu, so users no longer need to long-press a file to take actions.
More generally, thumbnail images have been made larger, shared files are now easier to spot, and the multi-column list view on iPad has been redesigned to be less cluttered and give items and filenames more room to breathe. Another welcome enhancement in version 10.1 is expanded preview support for over 130 file types, including Adobe Photoshop, Illustrator, RAW, 3D objects, high-precision DICOM, TIFF files, iWork Files, Java/C/Swift, and many more.
In addition, OneDrive now supports drag and drop, enabling users to drag files to emails and move them between open tabs on iPhone and iPad. Several iPhone X UI fixes are also in evidence, with the interface now displaying properly in landscape orientation, while a number of annoying bugs have been fixed, including one that made search results vanish whenever a file was opened.
OneDrive is a free download for iPhone and iPad available from the App Store. [Direct Link]