I just purchased my watch/fitness device. I downloaded the Zeroner health app (frog icon). Should I also install the Zeroner app (blue square icon with graphic)?
Yes, they're somehow the same apps only that one is newer (Zeroner) and provides additional details like:
• Pedometer/Steps calculation
• Calories burnt counter
• Distance/Time calculation
• Sleep monitor
When you install an app, there is the possibility to check its descriptions for each one of them: