Your iPhone 6S can already support wireless charging
Qi-compatible charging case for iPhone 6/6s/7, gold - INBAY
New For IPhone 6 Plus 6s Plus And 7Plus Wireless Charging Receive Coil #16Y | eBay
Wireless Charging Case for the iPhone 6 Plus / 6S Plus case - Aircharge
Qi iPhone 6 6 Plus Wireless Charging Receiver iOS
QI Standard Wireless Charging Receiver Case for iPhone 6 Plus / 6s Plus (Back Case)
How to Charge iPhone 6/6 Plus Wirelessly - iGeeksBlog
Wireless Charging Receiver Charger for iPhone 7 Plus 7 6S 6 Plus 5S 5 SE 5C UK | eBay
Wireless Charging Options For The iPhone 6 and 6 Plus - YouTube
Wireless Charging Options For The iPhone 6 and 6 Plus - YouTube
Iphone Qi Wireless Charger, Fast Speed Charging Receiver for iPhone 7 / 7 Plus / 6 / 6s / 6 Plus / 5 / 5s / 5c / 5SE Improved Adapter Coil Patch Module Ultra Slim 0.4 MM - Walmart.com
Qi Case Compatible iPhone 6S Plus / 6 Plus Wireless Charging Adapter
Amazon.com: QI OCEANLOVE Wireless Charger Charging Receiver Case for iPhone 7plus 6Splus 6plus (NO Battery) Built-in and Port Lightning Cable Data Sync Shockproof Protective Black : Cell Phones & Accessories