WebLauncher is a simple app that will launch a web page stored on disk in Safari (and only Safari).
No installation is required, the app should run from anywhere.
The web page (and all other content) must be stored in the
html folder inside the app bundle. The web page to be launched must be named
index with any file extension, so
index.htm are both fine.
To access the
html folder from the Finder, right-click on the app and select
Show Package Contents. Then navigate to
Contents > Resources > html. Copy your index page and related content to that folder, then just double-click the app in the Finder.
The app will not present a UI and will quit immediately after sending the open file message to Safari.