there are/were a few, some mentioned above. also essentialislam, i think its called
the problem is that very few questions are answered and its very slow. a few organisations/websites have tried but it hasn't worked out.
need a team of scholars to work together for this to be sustainable and successful. wahabis/deobandis have had theirs for a long time.
i hope dawateislami can get this sort of thing rolling, they already have the whatsapp service to answer questions for people of all countries.