PlatinumBuys via Amazon offers Prime members the GoPro WiFi Bacpac for GoPro Cameras for $17.49 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, it adds $5.74.) That's the lowest total price we could find by $10. It attaches to your GoPro camera, enabling long range WiFi remote control of up to 600 feet when used with the GoPro WiFi Remote (not included) or via GoPro's app for smartphone and tablets.

Of note, the original HD HERO camera is compatible only with the WiFi Remote.