If you can not connect to your Ticwatch 2 with your phone please follow the steps below.
The cause of the issue is that the OS and companion apps were updated several times after the retail models were already flashed and packaged. Therefore, on some phones there could be issues pairing the watches.
Please make sure make sure that your Bluetooth is set to visible to other devices.
Before you start, Uninstall the companion you downloaded from the Google Play Store. Restart your phone.
1. Please go to the Settings application on your phone and select Security. Then scroll down and enable Unknown Sources, please click OK on the notice that appears.
2. Please download the companion installer at the link below. When it is done downloading, please allow it to install. When the install screen appears, please select Next, and then Install.
https://drive.google.com/file/d/0B54nqo11wPjedXRqckRqcFZ4V2M/view?usp=sharing
3.Upgrade your Ticwatch system: after you successfully pair your Ticwatch, go to Settings > Update and click update. The system will download and install the newest 4.2.5_intl version.
4.Uninstall the temporary Ticwear companion from your mobile device after Ticwatch's system update. After that, restore your Ticwatch to the factory setting by long pressing the crown and check Clear Data to clear all your data.
5.Download and install Ticwear Global from the Google Play Store again. Log in and restart pairing by scanning the QR code on the Ticwatch.
If you have any question please reply to this post below.