UI Accessibility Plugin  Version 1.0.2
Make your UI accessible for visually impaired users
Android Development

Google TalkBack

The default screen reader on Android is called Google TalkBack. When it is active, it blocks all touch input coming in and decides what to let through to the application.
This regularly interferes with apps and games that need swipes and taps for their gameplay. There are a number of accessible apps on the play store that implement their own accessibility and require that TalkBack is suspended during play.
Different from its counterpart VoiceOver on iOS, TalkBack does not offer developers the option to query direct touch input when it is active.

The reason for this is simple and understandable: If an app could circumvent TalkBack (essentially disabling it), it could lock a blind user in the app with no way of getting back out. Without TalkBack, it would be impossible to find the soft key home buttons at the bottom of the screen. iOS devices all feature a physical home button on the device, so a lock-in would be impossible. There is always a way for the user to return to the home screen.
There is a blog post on the topic here: TalkBack, VoiceOver and Unity

This is why users must suspend Google TalkBack when using an app created with Unity.
The plugin will prompt users to do so when it detects TalkBack running.

NOTE: If you want to try it out yourself, TalkBack can be disabled by holding down the volume up and down keys at the same time.
Visually impaired users are usually familiar with this shortcut, as there are many apps that require TalkBack to be suspended (all Unity apps).

Advertisements, IAP, Facebook, Google Play etc

If you are using any native plugins on Android, for example to show advertisements or offer in-app purchases in your app, you might want to give an audio prompt to users to resume TalkBack to be able to interact with the native Google Play Store dialogs. This inconvenience is caused by the TalkBack and Android system architecture and cannot be circumvented.

Text Input

Text Edit boxes are only partially supported on Android, due to the above mentioned TalkBack issue.
The onscreen keyboard in Android is a native overlay, which means, blind users can only use it when they re-enable TalkBack. Apart from this inconvenience, edit boxes can be used normally.