After just one brew this is now a must have gadget for me. You can see the gravity drop even before any visible signs of fermentation appear so no need to peek inside the fermenter to check if it's started OK. Surprising how quickly the gravity drops - most fermentation over within 48 hrs. Then just slowly wait for the gravity to level out - no need to sample. Works fine inside a fridge which was my biggest concern but I'm using a plastic fermenter. A stainless one might be pushing it but you could perhaps place a repeater inside the fridge. One minor point - requires a micro-USB cable to charge; these are fairly uncommon now so may need to be ordered separately.