Has anyone used Photoshop for designing your app? If so what size measurements did you use e.g did you use the size of iphone 11 or ipad pro?
Yes you can use photoshop
Design on whichever devices you want your app to run on!!
People will typically design on the iPhone 11, or any phone with a notch because some people need to make adjustments for their UI to accommodate that
I’d suggest using Adobe XD instead. It’s free and simple to use to design a prototype for your app, as opposed to using Photoshop.