Why would a HI need a level/laser level? If something is not visually crooked, what instance would you need to use a level to “investigate further?”
I might be nice to know if an egg would roll off a counter.
For picture reference to prove yyour point. People someitmes don’t believe you if you tell them their home has settling in excess. A good picture of a level with your hand under one end shuts everyone up.
I can think of a few, but shower pan was the first that came to mind for me. Also, to help illustrate out of level or plumb components
I’ve used levels on garage floors, retaining walls, roofs (for my pitch app) in the house to show dips and such. I have a torpedo level for gutters.
There’s an app for that.
Bubble
Drain pipes,window sills,etc however to be honest prefer sitting a tiny super ball on the ground when demonstrating floors.
We carry levels as well as a laser, great for sloping floors.
To add to above comments, Exhaust Vent/Flue Pipes
My eye is calibrated to 1/4" +/-, so anything that don’t catch my eye, I leave alone. ;)
If you set a torpedo on top of the end of the four foot you can get a nice shot of the bubble and the tape measure.
I carry a lot of tools that i may not need on every inspection. Levels, moisture meters and much more. there are too many reasons to list why but suffice to say that if for no other reason i have them so if i need them i can document, quantify and validate any issue.
That’s what I was thinking. Without some reference, the photo is just a photo of the end of a level raised into the air. 
Thanks for the answers. I can see verifying sloped floors, counters, settlement etc. I’m still learning what is considered “within the scope” vs “beyond the scope.” I can definitely see how it would be useful for verification. It would sit in the car mostly but would be nice to have for when it is needed. But the bubble level app does seem like the most lightweight and inexpensive solution.
Agree, and the app won’t help if you use your phone for a camera
Simple, I like and I should have thought of that:roll:, Thanks Sam.:D:D
I recall a few/many years ago, someone posting pics of a level set on quarters. Made for an awesome reference. I searched but couldn’t locate the pics. For some reason, the names Frank Carey or David Valley come to mind. Whoever it was, if you see this post, please repost the pics and your story if you have them.
I use a level on AC units. Take a photo to illustrate.
Harbor Freight Michael, 2 foot level for $5. That and a golf ball work wonders.