I've recently installed an 80A Power Meter on the electricity supply to my house. It measures the current active, reactive and apparent power as well as providing a count of the total active and reactive energy. These reading are updated every second.
After installing a 100A isolator and pulling through extra cables, the installation of the power meter was relatively straight forward. It's in an enclosure with an 80A circuit breaker, located inside to avoid inconvenience if it ever trips and because the distribution board doesn't have enough space for it.
I intend to write an Android app for a real-time view but for now I'm just collecting historical data: