Include icon in manually created .app bundle From How to make a Mac OS X .app with a shell script? I recently learned of a hack for creating a .app file from a file folder which contains an application with resources.

The top folder is given the same name as a bash script in the top level of the folder system, except the folder name also includes .app.

What I'm wondering, though, is if it possible to set this .app to display an icon that I provide when the file is seen via the Finder? Or can this only be done by making my folder system a Bundle?
I believe you can change the icon by simply dragging and dropping the icns file onto the icon displayed in the upper left corner of the Get Info window. For example, if I right click on the test.app shown in the Finder on my Mac and select Get Info, I will get the following popup window.



Below is a folder with some icns files.



Dragging the os_centos.icns icon and dropping over the icon shown in the upper left corner of the Get Info window, will produce the following change.



You can convert files to .icns by visiting the website https://iconverticons.com/online/. Online conversion is free.