If we use PNG, for iOS we'll use @ x1 @ x2 @ x3 size per image (which is just a click on zeplin / sketch). Android: around 5 image sizes, which means that we must maintain 8 PNG images per graphic element.
while SVG – will work for iOS and Android, but there are technical limitations. For example, SVGs get distorted when they are processed. Although we could solve it by analyzing each element / layer of SVG more thoroughly through Sketch.
I hope someone helps us decide which is the best format to use in our application.