Accessibility & themes
FST is designed to be usable by as many people as possible. Accessibility is present at every level: text size, contrast, color-blind-friendly colors, voice reading, and compatibility with assistive technologies.
Large text and high contrast
- Labels and the main message are shown in very large characters, automatically resized to fill the available space.
- Grid buttons are large, colorful, and high-contrast, with a selection outline when chosen.
- Font sizes respect the system's Dynamic Type settings: if you increase the text size in your device settings, FST adapts.
Color-blind themes
The Theme selector in settings offers four modes. Beyond the System mode, three themes adjust the color palette to stay distinct depending on the type of color blindness:
- System — standard colors (for example Yes green / No red).
- Protanopia — red deficiency.
- Deuteranopia — green deficiency.
- Tritanopia — blue deficiency.
Depending on the theme, button colors are recomputed to maximize perceived contrast. For example:
- Yes / No: green / red in System mode, but blue / yellow in Protanopia and Deuteranopia.
- Numbers and Needs: blue may become cyan, orange may become yellow, depending on the theme.
- Pain scale: the gradient shifts from green→red (System) to blue→yellow (Protanopia/Deuteranopia) or cyan→red (Tritanopia).
These adaptations ensure that information carried by color (intensity, distinction between options) stays readable for everyone, without relying on hue alone.
Voice reading (text-to-speech)
Each selection can be read aloud in the system language, at an adjustable speed. This is a communication channel that complements the visual display, useful for both the listener and the user.
VoiceOver / screen reader compatibility
All buttons and screens have explicit accessibility labels and hints, as well as dedicated identifiers. The app is therefore usable with screen readers (VoiceOver), including to trigger the emergency alert or hide the controls.
Multi-platform
FST works on iPhone, iPad, and Mac. Some features, such as importing custom images, are available only on iOS (see Customization).