Mods can be exported but LearnToMod will not give you a .jar plugin file. However it is still possible to run your mods on a modified scriptcraft server. 

More detailed instructions can be found here:

9/5/2017 UPDATE: The ScriptCraft server may not be working with our servers at the moment. We'll update this page when it's been fixed.

4/2017 UPDATE: Our modified ScriptCraft server isn't compatible with Minecraft version 1.9 or higher. In addition to to above instructions, you'll need to switch to Minecraft version 1.8.2, right before starting the spigot server. Then switch the Minecraft version to the version currently compatible with our server (1.9 or 1.9.2) before connecting.

To summarize:

1) Unzip the file located here and put .js files into the scripts/<YourMinecraftName>/   folder.  A requirement is that the script contains a main function definition.  This is the 'entry point' for the mod, meaning where the code execution starts.

2) Switch to Minecraft version 1.8.2. Then start your server by navigating to the root of the scriptcraft_server on cmd/terminal, and enter the command:  java -jar spigot.jar . When you run the command, you'll be given the server output with the port number: Mine was *:25580) The root is the the folder you get when you first unzip the above file.  The scriptcraft_server folder is the root. 

3) Switch to Minecraft version 1.9 or 1.9.2. Log into your server from multiplayer -> direct connect -> (for the server address enter `localhost:<port>`) press join server

4) Once you log in, you should see a `(ScriptName) loaded` message.  Invoke the script by enter this command into the Minecraft console:  /js <YourMinecraftName>.<ScriptName>.main()

5) Check out the documentation for Scriptcraft here if you want to know what's possible:

How to Copy and Paste Code

Each badge or editor screen has a small gray JS button that allows you to view the code in JavaScript format. (located near the Simulator button). To copy the code, you'll have to do so from the freeplay modding section. At the top of the page of the freeplay modding section there's a drop down menu -- select copy. Then you can paste the code in a plain .txt document.