Amazon offers Prime members the TP-Link 50-watt Equivalent Dimmable WiFi Smart LED Light Bulb for $19.99. Coupon code "3TPLINKSAVE" drops it to $16.99. With free shipping, that's the lowest price we could find by $3. Using the free Kasa app, you can control this 11-watt bulb via your mobile device, including adjusting brightness and setting schedules. This Amazon best-seller features an 800-lumen output, 802.11n wireless, and voice control via Amazon's Alexa and Google Assistant.