Here's a list of 7 items that come in very handy when keeping reptiles and amphibians, compiled and used often by GoHerping! A few of these items are on the pricier side, however, it will be worth it in the long run to invest into any of these products.
Etekcity Lasergrip 1080
This infra-red temp-gun is really useful when it comes to checking hot spots, cool sides, and any other temperatures in your reptile's enclosure. Unlike using a gauge, you don't have to wait a few minutes, and I believe it's much more accurate than most.
Repti-Safe Water Conditioner
There are many ways to ensure your tap water is safe for reptiles, as small amounts of chlorine and ammonia in our water is much more harmful to herps. The easiest way I prefer is with Reptisafe drops, compared to boiling, distilling, etc.
Zilla Tropical Mist
If you need to increase the humidity in your enclosure, but don't want the substrate to be damp, tropical mist is pretty good at doing the job. It has a strong smell, but it also includes a few vitamins to help improve the health of your animals.
[small version] http://amzn.to/2kqlwA3
[large version] http://amzn.to/2kTpjTl
I found the timer really helps when it comes to keeping the animals' day/night cycles really accurate, without having to go around and turn every light on and off each day. At the same time, it can keep working 24/7 if I'm not home or gone for a few days.
These are pricey if you have multiple animals, however, thermostats keep your reptile's temperatures completely accurate if it's hooked up to a heat source. I can worry a lot less about the right temperatures if I'm using this with my animals who need very specific or high temps.
These are simply good to keep your hands from smelling like reptile food (mice/rats) and are useful when cleaning out enclosures to keep most of the bacteria off your skin.
Watch this video for more information!