Accessibility in Mobile Application Development

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We likely all know someone in our lives that may have accessibility concerns. It’s abundantly clear, especially in the last year, that digital access to services is a fundamental requirement of every day life when we have to live it further apart than we are used to. More than ever accessibility, ease of use and access to digital platforms is key to making sure that those among us who struggle with issues such as dyslexia, visibility, sight problems or general reading difficulties can access the services we all use day to day.

Mobile application downloads reached 33.6 billion worldwide in the first quarter of 2020 according to the Sensor Tower Q1-2020 data digest stating an increase of approximately 20% from 2019. Since the Corona-virus pandemic started at the beginning of the year both business and education app downloads have more than doubled. We know that approximately 15% of the worlds population suffer from some form of disability and that statistics show this number growing over the next 30 years. With this figure increasing it’s more important than ever to consider inclusion techniques within the mobile development sphere.

Text Readability

We know that image and video content perception can be an issue to people with vision issues. In consideration of this the aim is to ensure that most if not all content is represented by text. The text itself is still an issue, there are a few very important characteristics to consider.


Contrast sensitivity refers to the ability to detect differences between light and dark areas; therefore, if you have low vision, increasing the contrast between an object and its background will generally make the object more visible. As a general rule of thumb when designing content within an application aim to always use the highest contrast possible for the segment you’re implementing. Using light letters on a dark background or dark letters on light or white background is the simplest way to ensure that those who suffer from contrast sensitivity can identify clearing between content and background.

White text on a black background
Black text on a black background

Font Size

Also known as ‘Point Size’ is an important design decision. The screen real estate available to mobile developers can often vary quite widely between devices and as such font sizing can often be a difficult thing to correctly implement. The primary ideal here is what is the maximum font size we can allow within the app that won’t negatively impact the content delivery to the user. There’s no point allowing massive font sizes for there to then be the need to scroll endlessly to read the content, it defeats the intent. Instead the developer must test at least 4 primary sizes and determine how they are going to allow the user to adjust this within the app. The key things that we look out for while testing font sizes are:

  • As font size increases do we still avoid truncating text.
  • Does the app maintain a consistent information hierarchy regardless of the user’s font size choice.
    • This relates to the relationship between header, sub headers and standard content.
  • Avoid UltraLight, Thin, and Light font weights, which can be more difficult to see because of the way they contrast into the background.
  • Avoid using italics or all caps for long passages of text.

Font Selection

Font selection itself is incredibly important as how clear it comes through to individuals with visual difficulties depends on the features of the font type. people with astigmatisms either horizontal or vertical often suffer from blurring across those lines. Individuals with cataracts experience something more similar to the way a camera can un-focus on a point within it’s view-port.

Example of visual impairments vs Font Families.

Adequate Spacing

More often than not close letter-spacing in text can present visual difficulties for those who have central visual field defects. As a general rule of thumb having wider spacing where possible should be the default approach. There are various associations globally that have set recommendations on what this spacing should be, but it’s largely agreed that line spacing should sit at about 1.5.

Text to Speech

Text to speech has been around for awhile and developers should consider the benefits of implementing this within their applications. It can be a challenge sometimes to find a way to integrate this functionality keeping to the general layout and aesthetics of an application; but the benefits to users who have accessibility concerns or those with dyslexia usually out-weight these concerns, especially if the application is intended for public use.

Text to speech functionality is provided natively by both Android and iOS so that developers can make use of existing SDKs. This means that the time to implement text to speech functionality is minimal and in most cases the only significant time investment is the UX considerations of placement.

Artificial Intelligence

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In the last few years there’s been expedited growth in the artificial intelligence sector with a lot of previously difficult to use and develop processes being created for access and consumption by mainstream developers. This has meant that we can look at increasingly more modern and technically complex solutions to increasing accessibility of our applications to everyone.

We now have access to natural language processing so we can start to develop full voice operated content within our applications, we can identify a users intent and navigate them accordingly to the relevant content without the need for them to swipe endlessly. We can use this technology to help further break down the barriers between disability and digital services.

With a growing need to find practical solutions to improving on the implementation of accessibility within applications, something like the release to mainstream of technology to transform our text and image based applications into conversations between your apps content and the user are not far from being a reality.

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