fixing accessibility problems

[marceloeler]

Hi. I've been doing research on accessibility properties for mobile applications and I have developed an accessibility testing tool. I've found some accessibility issues in your app and I have fixed some of them as you can see in my commits. The main problems are related to:

• small touchable area: clickable elements dimension should have at least 48dp x 48dp
• Label, or speakable text: clickable images should have a content description so screen readers can inform users what is the action related to that image or image button.
• contrast: contrast ratio between foreground and background should be at least 3 (I haven't fixed any contrast related issue).

If you are interested in using my tool to find all accessibility issues to fix them and make your app more accessible for people with disability, please let me know.

Marcelo Eler