I do most of my Council stuff online via their web portal, also most of my GP stuff via (use to be EMS) https://www.patientaccess.com and book my next hospital app via their online bookings system so bonza!
PIP appeals https://www.gov.uk/government/news/new-online-service-launched-for-pip-appeals
Check area availability as it doesn't cover all areas atm
MoJ is also trying and failing atm to launch a PIP appeal via video link service. I've been having a few barnys with NHS services over disability accessibility/adaptation well lack of it. So think this is a good thing?
ESA appeals on line https://www.gov.uk/appeal-benefit-decision/submit-appeal England and Wales only
Upload your fit note https://www.gov.uk/send-fit-note
I think one complaint for all is that is doesn't send you a copy of your submission but you should be copy n pasting to a word doc (or what ever you use) for your own records anyway.
Imagine if the fully online Universal Credit service could do that?
Well apparently it might do in 2020 (only 6/7/8 who knows years after launch) but you might at present be able to ask your work coach for a 'to do' whereby they can enable a one off upload function on your journal.