Over the last few years I have written several articles showing how iOS apps built with different versions of Xcode would appear when run on iOS devices that didn’t exist when the apps were built. As a general rule, apps must build with the latest version of Xcode to opt in to seeing the native screen resolutions of new devices. Older apps would run on newer devices but appeared as letterboxed, pillar boxed and/or scaled versions of previous device sizes. This ensured that the old apps never ran at screen resolutions that didn’t exist when they were built.

In WWDC 2019: 224 Modernizing Your UI for iOS 13, the presenter discusses backward compatibility and…


In WWDC 2019: 206, Introducing SF Symbols Apple announced a great new resource for iOS developers:

SF Symbols introduces a comprehensive library of vector-based symbols that you can incorporate into your app to simplify the layout of user interface elements through automatic alignment with surrounding text, and support for multiple weights and sizes.

By the time iOS 13 was released there were 1,672 symbols available for developers to use in their own apps. However, 59 of them are restricted and can only be used to refer to particular Apple technologies such as iCloud or the Messages app.

There are a number of articles which describe how to use the symbols in your apps. One that I found particularly comprehensive is SF Symbols in iOS 13 by Antoine van der Lee. …


Adaptivity is an app which helps developers and designers visualise how iOS’s Size Classes and margins for layout, readable content and the safe area look on real devices and how they change with respect to orientation, iPad Slide Over/Split View and Dynamic Type size changes.

In the full paid version of the app, Adaptivity (A), there are also screens to explore System Colors, System Images, System Materials and Table Views. …


Geoff Hackworth

Independent and freelance software developer for iPhone, iPad and Mac

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store