Want to connect multiple Bluetooth speakers and headphones to one smartphone? Here's how you can do it - India Today
Upgraded] Anker Soundcore 2 Portable Bluetooth Speaker with 12W Stereo Sound, Bluetooth 5, Bassup, IPX7 Waterproof, 24-Hour Playtime, Wireless Stereo Pairing, Speaker for Home, Outdoors, Travel - Newegg.com
Bose SoundLink Bluetooth Mobile Speaker II review: Bose's Bluetooth speaker gets even better - CNET
Bluefruit LE Sniffer - Bluetooth Low Energy (BLE 4.0) - nRF51822 [Firmware Version 2] : ID 2269 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits