It took a couple of days more until the first usable version was ready to be used. While working fine on macOS, it took me a couple more to fix some several bugs that appeared on the other platforms.
On Windows, for example, the program was throwing an exception when using rounded borders. On Linux, you couldn't drag the result out of the window. I had to disable these options temporary and find a workaround to ship the Linux version.
There are rough edges, for sure, but in general, works.