The worst problem of round smartwatches is using those apps that are not supposed to be used in this kind of screen. So you will have cut edges and other annoying issues using them.
So all of these smartwatches can switch between a “full” mode and “small” mode, but I always found it very uncomfortable, because most of the time, you need to switch multiple time to perform even the most simple task.
Let’s come to the solution. This app is able to launch your apps in some windows. They can be moved, resized, pinned, closed.
You only need to put the desired app in the whitelist. All the apps that are not in there, will be launched fullscreen as usual.
In the option you can set the size of floating windows as you wish. Personally I use 80-85%.
This is an Xposed module. So you need to have root access and install Xposed repository.
Xposed xda forum - for Zeblaze Blitz (Android 5.1) version sdk22-arm is working