How to root for Zeblaze Blitz 3G

Thanks to this site xdadevelopers_zeblaze and split52 who developed the rom, I could succeed to root my smart watch.
The above site is not for beginners like me. So I make this detailed procedure.

First, you can check the result of the rooting here:

I am not responsible for anyone's issues here. Use this at your own risk!

Procedure

1. Backup your device or Download the Stock Rom
2. Download and Install "Blitz USB Driver"
3. Install SP Flash tool
4. Download and Install the custom rom with TWRP
5. Download and Install ADB and Fastboot tools
6. Copy the rooted rom to your watch
7. Install the zip in the TWRP recovery

1. Backup your device or Download the Stock Rom

• In my case, I just downloaded the stock rom from here

2. Download and Install "Blitz USB Driver"

• You can download the driver here
• The usb driver is included in the zip file under the "com_v1.12.50.0" folder.

3. Install SP Flash tool.

• You can download the newest version here
• Refer to this site

4. Download and Install the custom rom with TWRP

• You can download the TWRP 3.0.2-1
• Run SP Flash Tool (flash_tool.exe)
• Set Options as follows:
  
• Select the "MT6580_Android_scatter-Zeblaze-Blitz.txt" file for the Scatter-loading File under the twrp-3021-Blitz folder
• Make sure that the 'Download Only" option in the SP Flash Tool as follows
  
• Click the "Download" icon
• Power off your watch and connect the watch to PC using the charger
• Wait until the process completes and a "Download ok" box will appear with green tick
• Refer to this site for dowloading
• Refer to this site for installation
• You might want to use Android One Toolkit

5. Download and Install ADB and Fastboot tools

• You can download the tool program here
• Refer to this site for installing the program
• Enable USB debugging on the developer setting of your watch

6. Copy the rooted rom to your watch

• You can download the rooted rom. It is created on 13-10-2016.
• You should have enough sd card space in your watch to copy the file. It is about 445MB. In my case, I had to uninstall apps and uninstall the updates of the default apps such as Google Play Service.
• Copy the zip file in the sd card of your watch where you want. e.g. Downloads

7. Install the zip in the TWRP recovery

• Make sure that your watch is on
• Connect your watch to PC using the charger
• Run the ADB and reboot with recovery mode. In Windows, you can run 'cmd', and then type the following command:

adb reboot recovery 

• Then the watch will be in TWRP recovery mode. If not, try again the "adb reboot recovery"
• In the TWRP recovery mode, select Install -> Install Zip and select the zip file where you copied
• Make sure that the "Zip signature verification" is unchecked
• Finally confirm the installation
  
  
  
  

Cautions

• After rooting, Do not change the "App List Style" in the setting. When I did, the watch became dead. So, I had to re-install the rooted rom.
• After rooting, calling from history does not work. But calling from contact list seems working.

Troubleshootings

• If your watch became bricked, please do the following (refer to this):

Hold power botton for a while, when your phone give balck screen release power botton, your blitz back to charger mode, now you need flash a rom.