Servoy mobile is using JQueryMobile especially for all GUI, this means its default available and ready to use and access from servoy script methods.
See official API docs, for how to utilize the library. The widgets part might be of most use inside Servoy Mobile.
//To show a loading indicator
$.mobile.loading('show', {text: 'Hello World', textVisible: true});
//to hide it again
$.mobile.loading('hide') |
$.mobile.defaultPageTransition = 'slide' |