WordPress E-Commerce Site Enhancements

I manage several live WordPress e-commerce sites and need a reliable designer-developer to jump in whenever updates are required. Day-to-day work ranges from refining layouts for a smoother user experience to tightening mobile responsiveness, and I also regularly request fresh content uploads... (Budget: $2 - $8 AUD, Jobs: HTML, PHP, UI / User Interface, Web Development, Website Design, WordPress, WordPress Design, WordPress Plugin)