I'm using PNG Express to extract asset from Photoshop. Is there any supporting plugin for Adobe illustrator to extract the assets?
I don't use any extra plugins to export .pngs in Illustrator. I've found that using a single large artboard and creating named slices work well to export multiple .pngs. Simply create the slices you want and then use File > Save for Web and either leave All slices selected or choose the slices you want.
I then optimise the exported files for the best performance using ImageOptim on Mac or FileOptimizer on Windows.
Illustrator works nicely for mobile design as it can produce scalable .svgs, saving a lot of hassle working with various high dpi screens.