For a full range of gauges, if you have a Mercury outboard you should checkout "Vessel View Mobile". For $275 you get a module you attach to the engine which transmits a wealth of data from the engine to your smartphone or tablet.
https://www.mercurymarine.com/en/us/news/announcing-vesselview-mobile-now-available/
See SmartCraft® engine parameters like Engine hours, fuel burn, water temperature, battery voltage, RPM, etc. (parameters available are specific to each engine family).*
Get fault code diagnostic information so you know and understand if that fault is something to be addressed when you return to the dock, or is more urgent.*
Fuel Management provides accurate fuel usage data along with fuel remaining plus indicate time and distance to empty when the user enters fuel added via the app.
https://www.mercurymarine.com/en/us/gauges-and-controls/gauges-displays/vesselview-mobile/
Demo Video