Tip 1: Usability test
Your app (design prototypes and working software) should be tested with real people, ideally face-to-face. To achieve this, contact a market research company to help you recruit participants. (Try Farron Research; Focus People; Ava Research just to name a few).
Whilst testing your design may seem overwhelming, Nielsen Norman Group (NNG) suggest that five people are sufficient in revealing major usability issues in your designs.
The brief you provide the market research company to find participants (known as a recruitment brief) should be reflective of the target users of your product.
One criteria that is often overlooked is that close to 20% of Australians live with a permanent or temporary disability (vision impaired, cognitive and motor disabilities). Therefore at least 1 in every 5 participants you recruit to test your product should have a permanent or temporary disability.
Tip 2: Apply good colour contrast
Designs should have sufficient colour contrast to make it as easy to see. Tools like Colour Contrast Analyser (available on PC and MAC) can inform whether your designs have sufficient colour contrast.
- Small text should have a contrast ratio of at least 4.5:1 against its background.
- Large text (at 14 pt bold/18 pt regular and up) should have a contrast ratio of at least 3:1 against its background
- Icons and other critical elements should also have recommended contrast ratios.
Google Material Design provides additional information on appropriate colour contrast. Visit Google Material Design - Accessibility Colour and Contrast for more information.
You might also be interested in our blog article on colour contrast.
Tip 3: Ensure appropriate touch target
To allow the best usability and ensure people with different fingers sizes or mobility issues to successfully interact with your app, the recommended target size for touchscreen elements should be 7-10mm on the screen.
For Android, this equates to a touch target of 48 x 48dp (approximately 9mm). For example, an icon may appear to be 24 x 24 dp, but the padding surrounding it should comprise the full 48 x 48 dp touch target. Visit Android's Material Design Accessibility guidelines for more information.
For iOS, it is recommended that touch targets be at minimum 44 x 44pts. Visit Apple's Human Interface Guidelines for more information.
In most cases, touch targets should be separated by 8dp of space or more to ensure balanced information density and usability, and reduce the likelihood of the wrong element being tapped.
You might also be interested in our blog article on touch targets.
When including animated GIFs or other moving content, consider the following:
- Ensure that moving, blinking, or scrolling content can be stopped, paused, or hidden
- Ensure that there are no more than three flashes per second in content
- Reduce contrast, luminosity variation, and red saturation of content
You might also be interested in our blog article on animated GIFs.