Converting Scratch 3.0 Project Files directly to Android Package Files (.sb3 to .apk conversion) is not super straightforward, but it seems to be possible.
Try the following steps:
- Create a project in Scratch.
- Use 'Share Project' function.
- Copy the shared project's URL.
- Go to Phosphorus online tool.
- Paste the shared project's URL into given field.
- Select 'Package' option and copy the full URL.
- Go to AppsGeyser (an appmaking tool).
- Select 'Create App' -> 'Website' options
- Once prompted, use the URL that you created earlier.
- Now you can download the Android app in .apk format.