Day to day
What it actually tells you
How much is in there, right now
An actual level, and an actual number of litres once you have told the app your tank's litres per metre. Check it from the house, from town, or from another state.
What you are using
Individual events: the shower, the washing machine, the stock trough, the irrigation cycle. Daily summaries and overnight totals, so you can see where the water actually goes.
Whether you have a leak
A slow overnight fall that should not be there is the signature of a leak, and it shows on the graph long before anyone hears a pump running dry.
How long you have left
Your recent usage is fitted and projected forward, so a water delivery can be booked with warning instead of in a panic.