Bong
The extraordinarily useful Big Ben Twitter account tweets BONG every hour & the number of BONGs it tweets will inform you of the hour. Who says Twitter is useless?
Actual favourite Twitter feeds: Very British Problems (samples: “Expressing your rage by saying ‘you’re welcome”’ as loudly as possible”, “‘I’ll bear that in mind’—Translation: I’ll ignore that completely”) & Riker Googling, which informs us of No. 1’s uncleared searching history (samples: “evasive maneuvers keyboard shortcut”, “acknowledged emoji”, & “kobayashi maru let’s play”).