The warnings that apply to the computer version also apply to AnkiMobile.
In addition to the above, another thing to be aware of in AnkiMobile is that your code also needs to play nicely with AnkiMobile’s tap detection. Taps on A/BUTTON elements, or elements that have an onclick handler should work as you expect.
If you have other elements that must receive tap events, give them the class 'tappable' to tell AnkiMobile 2.0.39 or later that it should pass taps through to the element.
To change the styling of the audio replay buttons, please see https://docs.ankiweb.net/templates/styling.html#audio-replay-buttons
When you attach an image from the photo gallery it is automatically resized to have a maximum length of 1024 along its longest edge.
Recent Anki versions allow you to customize this limit in the Preferences > General screen.