There are two kickstarter devices that are going to be shipped quite soon

First one is iWinks's Aurora which works on the same basis that Stephen LaBerge's own lucid dreaming induction device did. It is a headband that detects whether you're in a dream (REM phase) and flashes setup by you lights color and pattern to help you become lucid.

This kind of device combined with WBTB n' MILD gives highest lucidity success rate possible according to LaBerge

Spoiler for example way to do it:


Second is one that works the way you mentioned in OP, The Luciding's LucidCatcher.
It detects rem phase, same way as aurora but instead of lights, it zaps your brain (cerebral cortex) with safe? Alternating Current of 40 Hz
It might be able to cause lucidity but there's no confirmation beyond one study that a lot of people called biased, so i'm skeptical about its working.
And I don't really like idea of zapping my brain with electricity.

I don't own Aurora or any device for lucid induction though, so you won't get firsthand experience from me
Also, both of these devices are supposed to be shipping 2018 February - March, so we might get some firsthand experiences posted around here. Both are on kickstarter and got their websites if you're looking for them.