Flume hijacks the same signal that the utility water meter uses - magnetic pulses as a disc or piston oscillates. This makes your meter the "one version of the truth", and also gives you a reading at the point where ownership transfers from the utility to you.
Streamlabs makes a nice product (as do Phyn and Flo), but it is necessarily further downstream.
Side note - I just discovered an outlier problem that none of these would solve. I have a very slow leak shortly after my water meter. It is 150 feet from my house, so not really a fit for a Streamlabs-type solution. It seems to be below the low flow detection capabilities of the Zenner PPD (0.125 gal/min) - if it doesn't spin the meter, then Flume cannot detect it. Unless I find a catastrophe about to happen, I will just let it keep drip-irrigating the Ocotillo planted near the meter box.