Recently, we received comments that some customers can’t pair F2 with his phone. ‘The equipment binding another account, unbinding first.’ A message shows up whenever you try to pair it. Sorry for inconvenience. NO.1 will tested all products before they are listed. But some forgot to unbind their accounts just shut it down and package. Our engineers worked on this as soon as we received such comments. They created an app called ‘分动手环 test’ to solve such issue. Sorry, no English version so far. Here I want to make a tutorial about how to use this tool. I take a F2 which is binding another account. First I tried to connect it with my phone, a message shew up, I can’t connect it with my phone. Then I shut off the Fundobracelet app and turned to the ‘分动手环test’ app. 1, Click ‘蓝牙连接'(Bluetooth connection) button. 2, Then in the next page, you need to turn on Bluetooth on your phone. Click ‘开始搜索'(Search) button, until you find F2 in the below. 3, Click to pair F2. If you connected it successfully you’ll get a’蓝牙连接成功'(Bluetooth connected) Now these two devices are already paired up, you can control F2 via Bluetooth. 4, Click ‘解绑命令'(unbinding command)button. Done. You have removed the others’ account on your F2.     Shut off Bluetooth on your phone and turn it on later.(Yes, you need to disconnect the connectivity first) Back to the Fundobracelet app, reconnect it. These two device will pair up successfully. This is the app, download: https://drive.google.com/file/d/0B1wvhNT7Y1TmNFI3TnR3X0pwcFE/view?usp=sharing Hope it helps, if you have