I have the Seagate Wireless Plus drive and I believe it will do what you are asking but, just so you know, if it is connected via USB to your xbox then you can't also connect to it at the same time via wifi.
You should be able to connect via wifi from your laptop to copy files to it, then connect it via USB to your xbox to use them. I don't see any advantage to doing it that way since USB transfer is faster than wifi so you may as well connect via USB to your laptop, copy the files, then connect to your xbox.
Kingston also makes a similar product, Kingston W-drive
. They are smaller in capacity but use solid state memory instead of a spinner.
You can use an app to access it from iOS or Android but it is also accessible from a device with a browser.
I use mine to carry movies with me that I can access via my Android phone or Android tablet, it works great for that and gives me 1TB of storage.