With my converter, you can convert your Scratch projects into SWF files. You may not know that you can also convert SWF files into standalone applications for your operating system! This guide will only cover converting them into EXEs and macOS applications, although it is also possible to do this for Android and Linux.
This conversion works by packaging your SWF file inside a Flash Player, similarly to how your Scratch project is packaged inside the SWF! This means that you will need to download a Flash Player to package it in. The best version to use is Flash Player 11. You can download it directly from Adobe's server here (about 150 megabytes). Once you have downloaded the ZIP file, extract it. Inside, you will find three folders, one ending in 32bit, one ending in 64bit, and one ending in debug. Choose the first one because it contains the standalone Flash Players. Now, continue to the section for your operating system for instructions on which one to use and how to do the actual conversion.
If you are on Windows, you will want to convert the SWF to an EXE file. Open the item called flashplayer11_2r202_235_win_sa_32bit.exe (32-bit standalone Flash Player 11 for Windows). Choose File > Open..., press Browse..., and select the SWF file you want to convert. Then choose File > Create Projector.... Now you can save the converted EXE.
If you use a Mac, you need to convert it to a macOS APP. Open the flashplayer11_2r202_235_mac_sa.app.zip file, which will expand to an application called Flash Player.app. Open Flash Player.app, and choose File > Open.... Select the SWF file that you want to convert. Then, choose File > Create Projector... and save the converted macOS application. Occasionally, when you open the Flash Player app, you might encounter an error stating that it is damaged or by an unidentified developer. The easiest solution is to use the command line. Open Terminal, and type the following command.
Make sure that there is a space after the command. Now, drag the Flash Player app into the Terminal window. It will should say something like this:
cp -RX /Users/junebeetle/Desktop/Flash\ Player.app
Then, add a space, and then the path to the folder you want it to put the fixed copy. In my example, I use the Desktop. This works well, I'd suggest that you do the same if you are not used to the Terminal.
cp -RX /Users/junebeetle/Desktop/Flash\ Player.app ~/Desktop/
The ~ (tilde) means your home folder. Press Enter, and you should see the Flash Player app appear on the Desktop. This copy will (hopefully) open without trouble. Now, you can follow the steps above to convert the SWF to an app using the fixed copy.