Epic fail: "The messaging app has users in 250 countries".
There just simply aren't 250 countries.
(At the time of posting, parent was below zero)
http://en.wikipedia.org/wiki/List_of_country_calling_codes has 275 in their complete listing; but then, quite a few aren't "countries"
If the definition Wolfram cared to use was "Passport issuing state recognised by other passport issuing states" then we might agree.
The UK is a single state, but comprised of at least three countries. England, Wales, Scotland. Northern Ireland would not count as a 'country' I guess, though Ireland itself obviously is.