Just a little update: on Android 4.0-4.3 SMIL animations are not working, so we should use the “android” spinner, which is the one also available via JavaScript animation (as stated in the docs ion-spinner - Directive in module ionic - Ionic Framework)
Each spinner uses SVG with SMIL animations, however, the Android spinner also uses JavaScript so it also works on Android 4.0-4.3.
So, I think we could change the request in “Can you make the other spinners as JavaScript, too?”