I love X-plore File Manager....it's a very small, memory friendly, dual pane file manager with simple built-in file viewer / players that can be deselected in favor of one's preferred viewer / player (handles apks & zip also)....this thing is totally free, but with donation there are so many file sources & sharing capabilities open to users that looking to any other file manager is rather pointless. One caveat is that although this app does provide an internal user configurable setting to enable OTG USB STORAGE DEVICE ACCESSIBILITY, I've yet to successfully mount or browse my OTG USB drive which is actually my 'old' 256GB Samsung microSD which has no errors or formatting problems and is viewable in two other OTG-capable file managers. ES File Manager was my go-to app for MANY years until it was purchased and bloated to junkware by Cheetah....who's apps I simply REFUSE to use. Ever. If you need to have a reliable, trustworthy, easy to use, full featured, R/W capable, OTG-USB storage ready file manager on your HTC10 or similar Nougat AOSP smartphone, I can verify and attest to the rock solid performance in ASUS' FILE MANAGER from Google Play and Asus.com. I love the fact that upon plugging in my OTG USB adapter (holding mircoSD), a quick refresh or re-opening of the app immediately graphically updates the total number of available drives, correctly lists them and gives a very easy to read 'quick reference' that color codes by file type grouping, ie., VIDEO, AUDIO, PHOTOS, PDF, etc and shows the amount of storage consumed by each group. It's nice because it will generate thumbnails for many types of video files that other file managers simply won't even attempt to thumbnail. Highly recommended...also TOTALLY FREE!