In my most niche work, I would take 100-frame macro stacks of the insides of watches for clients. This was as fiddly as it was laborious as I didn't have automated rails for this sort of thing; I would just have to leave some overlap between each frame and hope the stacking software didn't defecate the proverbial bed. However, one enormous quality-of-life improvement I made for these sorts of shoots was the tethering of my camera to an iPad. This allowed me to see more clearly, not get marksman's fatigue, and to take some really interesting behind-the-scenes images too.
In this video, Alejandrino uses some Accsoon products that allow him to stream his camera's view to his iPhone or iPad by being tethered to them. If you shoot any sort of behind-the-scenes footage, this could be invaluable, but above and beyond that, it can be useful for certain shoots and improve your final images.
I don't get it, I can maybe see tethering to an iPad if you're in a studio or something and you and/or the client wants to the see photos right away, but an iPhone? Just seems like a waste of time and $$$, but to each their own. Just my 2 cents...