Honestly, iPhone works fine, but if you prefer a bigger picture then you may like to use an iPad like my girlfriend does. Either works fine.Looking to use Shot Marker my club has. And maybe buy one of my own. I have seen people use there phone, Tablet or lap top. Is there a best option.
And know how to adjust the power settings so the darn thing doesn't go black between shots.Best option is the one you know how to use, navigate to websites, switch on/off wifi, connect to different wifi, click/touch buttons, and see the screen easily. Bigger screens have some benefits, and if using a laptop I would want touch screen along with the keyboard. Ipads overheat in the sun more than some others, I'm sure at a certain temp they'll all overheat. Covered lines help that.
I use my phone or a cheap refurbed 10 inch Amazon Kindle fire I got for $60 and have had zero issues with it.