Yes, DocHub is fully optimized for most newer touchscreen devices.
Some of the tools will need to be used a little differently due to the different type of interface. For instance, the Sign menu normally uses drag/drop to add signatures, initials, or today's date, but on a touchscreen you'll want to tap the one you want in the Sign menu and then tap the place on your document where you'd like to add it. Then, you can move it around after it's been applied by tapping on it, holding your finger down while moving it, and release your finger.
If you do experience an issue in DocHub while using a touchscreen, please let us know by submitting a support ticket and include as many information as possible about what's not working properly and include details about your specific device model.