Here with some accessibility pointers is The Guardian. Take a look:
Talked to people with accessibility needs for point two? Test with them before (and after) your app is released. On iOS, developers are using services like TestFlight to put beta versions of their apps into the hands of testers before submitting them to Apple for approval – a golden opportunity to find out early if your app is falling short.
Meanwhile, once an app is released, it’s important to keep testing it, especially when there’s an update for the operating systems that it’s available for. Accessibility technology, and features in iOS, Android and the rest, are evolving steadily, so even if your app was accessible when it was released, don’t assume it can’t be improved after that point.
There are a few other great pointers for developing apps in general, but this one I found to be particualrly helpful:
Simplify wherever possible
Another accessibility principle with benefits beyond any particular group of users is simplicity. Cramming features, menus and on-screen prompts into an application is an easy road to go down, especially when you’re the developer, and so know your way around them.
Less options, clearer prompts and a well-defined pathway around the application are improvements that will pay off across the board, but they’ll be particularly appreciated by people using screen-reading technology, or just people who are fairly new to smartphones and apps.