I have a question about running fit and finish testing on mobile devices. For checking designs, the test usually involves measuring the pixel width of on-screen elements for webpages or native apps on iOS and Android.
Originally I was taking screenshots of the application and using an on-screen ruler to measure the pixel width on the PC. This is not really feasible, I've realised because of the device independent pixels (DIPs) that are being taken on Android. I'm not as familiar with iOS but I assume that iOS was doing the same thing.
So how do I measure pixel distances like that if the DIPs are what are being taken on Android. Usually what I end up measuring varies according to the device.
What would you say are the appropriate methods for measuring on-screen distances on mobile devices?