Sometimes, we need our moblie phone to connect 2 or more bluetooth devices. You get your smart bluetooth bracelet/watch conneting with your mobile phone via bluetooth, but you also wanna listen your favorite music by bluetooth headphones, such as true wireless earbuds. Is it possible to do this ? The answer is YES. Actually your mobile phone can connect up to 7 bluetooth devices at the same time. However, only one pair of bluetooth headsets or speaker can be supported at the same time. That's why ? Please check as below:

The logic address of bluetooth is 3bits which can indicates 8 logic links, and the 000 indicate broadcast, other 7 can connect 7 devices. 

In theory, a Bluetooth master, that is, your mobile phone can connect seven slave Bluetooth devices. But in the case of ESCO connection, ESCO retransmission will use the second logical address, which will reduce the number of slave devices in the piconet. However, when multiple Bluetooth headsets or speakers are connected at the same time, only one Bluetooth player will work, which is limited by the sound card of the mobile phone. The sound card can only be provided to one Bluetooth headset or speaker.

So, you can listen to your favorite songs via bluetooth speaker/earphones from your phone and at the same time you can use the sport watch/bracelet App on your mobile as well. Even you can add some other bluetooth devices connecting to your mobile phone via bluetooth connections as long as it's not for sound out put. Such as bluetooth remote controller, to control the music play, remote selfie, PPT play, etc. One magic ring as below for your reference.

Magic ring -bluetooth audio remote controller