I've seen quite a few misconceptions about the Sleeptracker and other similar devices around the net on how they work and their benefits for lucid dreaming - I'm afraid all these devices are almost totally useless for the ways in which many lucid dreamers would use them - the only benefit being the ability to asses sleep patterns retrospectively (which could be very interesting).

These devices detect muscle movements in your body which occur in the nearly-awake stage of sleep, this happens in cycles AFTER REM, so you'll have passed your ideal phase for LD and that includes all techniques; WILD, MILD and all the other more exotic four letter acronymized methods.

Part of the reason for the misunderstanding is probably the marketing, which covers up the fact that it really is just a motion sensor (much like the one in your Nintendo Wii though perhaps more sensitive) inside a rubbish looking watch.

...Can you tell I’m jealous of having not invented it first?