Removing Titlebar & Window Transparency
Both of these can be set when you create your window. These 2 parameters are all you need - no_titlebar and alpha_channel.
When creating a window without a titlebar you create a problem where the user is unable to move your window as they have no titlebar to grab and drag. Another parameter to the window creation will fix this problem - grab_anywhere. When True, this parameter allows the user to move the window by clicking anywhere within the window and dragging it, just as if they clicked the titlebar. Some PySimpleGUI ports allow you to click on input fields and drag, others require you to grab a spot on the background of the window. Note - you do not have to remove the titlebar in order to use grab_anywhere
To make your window semi-transpaerent (change the opacity) use ghe alhpa_channel parameter when you create the window. The setting is a float with valid values from 0 to 1.
To create a window like the one above, your window creation call would look something like: