Very nicely done. I would recommend either a simple tooltip popover for each button on first startup, or a simple help button somewhere. It took me a while to r

Very nicely done. I would recommend either a simple tooltip popover for each button on first startup, or a simple help button somewhere. It took me a while to realize/notice that the snowflake button was to freeze the frame. I wouldn't want to clutter the elegant simplicity of this app, but it was confusing to me initially.