Best icon sizes to use for Android / iOS

Question

I'm writing Delphi app for android/iOS phone/tablet using TImageList.

My max icon size available is 96x96. should I provide 3 sizes 24x24, 48x48, 72x72, 96x96 or should I provide 3 sizes : 32x32, 64x64, 96x96 or 24x24, 48x48, 96x96 (is 3 more than sufficient?)

in TImageList.

thanks.