If you'd like to avoid a full rewrite of your store, our app ShopPad (https://apps.shopify.com/shoppad) may be a good answer to combat Google's "Mobilegeddon"
I don't want to turn this reply into too much (more) of an ad, so I'll just suggest you take a look at our Shopify app store listing and see why 30,000+ stores use ShopPad for their mobile solution.
Any questions feel free to contact direct: aaron [at] theshoppad com