Limitlesstravel.org is a website dedicated to providing clear information about access, whether that is physical access or other issues such as hearing loops, use of sign-language or the family-friendliness of venues and attractions – all in London and fairly central as far as I could see but all the main ones are there, with user-reviews as well as general information.
For each attraction, you can see if wheelchair hire is available, if assistance dogs are allowed, if there is a hearing loop and various other details which would help you decide whether to visit or not. The hotels list if there is a shower seat, raisable beds, grab rails, emergency cord, adjoining room and lots of other details, which, again, make the difference as to whether or not you would give them your business.
You can search for a specific attraction or filter for different types of access or search on the map.
Looking at some of the press coverage on its own site, some refer to it as a guide to London, others as a guide to the world, so presumably they intend to expand as it does appear to only be London for now, unless I’m missing something, but it is definitely worth exploring this site if it’s London you’re heading for and need access information on hotels or attractions.
See my links page for other useful websites.