Electronic meters:
There are plenty of electronic pH meters out there, ranging from all-in-one sticks to things like the American Marine pinpoint with detachable probe. Note that ph probes require you to store them in a special solution, and have a limited lifespan
There are also plenty of electronic TDS meters out there, which can be useful if you raise shrimp.
I've not seen any well reviewed meters for other freshwater relevant parameters (ammonia, nitrite, nitrate, kh, gh, etc).
Other tests:
API and other vendors make freshwater suitable tests for phosphate, Iron, KH/GH and a few others..
I guess the big question is: Why do you want to test, and how much do you want to spend?
Personally I own:
API FW master kit
Salifert nitrate test
API phosphate
API KH/GH
HM Digital AP-1 TDS meter
At the start, I used ammonia and nitrite tests regularly, to monitor cycle.
I have started doing KH/GH tests with water changes, as it seems my local supply varies, and I am actively monitoring this after a fish loss.
I use the nitrate and phosphate tests to monitor my dosing when I mix new fertilizer solutions, but they are otherwise mostly idle. Maybe once a month I test these two, along with TDS just to see how things are going with my fish load.
Pretty much everything else sits idle unless problems crop up.