While not exclusive to our industry, I think cameras and lighting have made a big difference. We use to use Polaroid cameras to try and get images "now" and regular film was never a sure thing. You took two dozen pictures and maybe half were usable. Being able to shoot stills and video and see it now saves time and money. Flying drones at low cost could help inspect duct work and do quality control, if you see dust blowing around with lift fans going you're not done. The ability to put a camera on them, or almost anything is a big advancement.
The LED lights available today give good battery life and bright light. As LED's become more prevalent the technology and energy use should improve. It's a lot easier to do a job if you can see what you are doing.
GPS is also a handy thing to have especially for a service vehicle. They are incredibly helpful in areas where you are not familiar with the roads. One problem I have found is they decrease our "Map Aptitude" our ability to use maps and knowing the most efficient way to get around. On any typical day I can cut miles off the route the GPS has chosen. That being said many have "fastest or shortest" settings which can help them work for you better. Doesn't it always seem the day you need it to work, you find yourself staring at a farm field or a river and she is telling you to turn right in 500 feet. Mask and snorkel must be optional.
John