Mobile Accessibility User Interface Recommendations
Mobile Phones present different modalities of interaction that are not found in the desktop computer. This requires developers and designers to think differently about their user interfaces. Consider the commonly accepted UI Guidelines below when building your mobile application.
Use UI elements that are designed for touch gestures to make interaction with your app feel easy and natural.
Text should be at least 11 points so it's legible at a typical viewing distance without zooming. Developers should make text dynamically resizable without ruining the UI.
Make sure there is ample contrast between the font color and the background so text is legible.
Don't let text overlap. Improve legibility by increasing line height or letter spacing.
No WCAG Guideline
Always display images at their intended aspect ratio to avoid distortion.
Create an easy-to-read layout that puts controls close to the content they modify.
Align text, images, and buttons to show users how information is related.
The guidlines above were adapted from Apple's UI Tips