I agree Sentinel is looking good. However I'd like to add several xpubs. A merge between Sentinel and Bitcoin Balance would be ideal. Do you know how to contact the Sentinel devs?
I don't care about mobile friendliness in a browser so much. I'd rather have a one tap app, instead of having to: open browser, navigate to the page, login, etc.
Have a look at Coyno. You can enter several xpubs from MyCelium, Trezor, Electrum etc.. and can also add in single addresses if you want.
Gives you a nice overview of your total holding.
https://coyno.com/