I searched for digital water test aquarium and quite a lot came up.
Most test are separate divices, though.
www.fishlab.co.uk/
I like the liquid test sets.
It makes me feel like not all time studying chemistry at school was a total loss.

Mind you not all tests will be needed continually.
I never measure ammonia, pH and nitrites anymore for i know the levels are steady.
I tested weekly when i started with my tanks and kept adding to the bioload to see how far i could go.
I never got any ammonia and nitrite readings even with a totally overstocked tank.