I've used a dozen different electronic tester ($20.00 to $300.00) and have returned or trashed them all. First of all you get what you pay for. Those that cost a lot are accurate but need to be calibrated with a buffer solution of a known pH value (usually 4.01 & 7.00). If the device doesn't require calibration I'd be very skeptical of the results.

The drop test is best unless you have difficulty differentiating colors, then the electronic testers may be the best for you.

If you search this site there have been lots of opinions offered. Seems like most are negative.