title: Using a Custom Function in a Google Spreadsheet?
body: <p>I'm trying to figure out how I can write and run a custom function in a Google spreadsheet and I've been following this <a href="https://developers.google.com/apps-script/execution_custom_functions" rel="nofollow noreferrer">google tutorial</a>.</p>
  
  <p>However at the time of this posting, I fear that this tutorial is out of date. I followed the steps, but see no way to access my <code>in2mm</code> function from within the spreadsheet that I started at. The tutorial suggests the following to make it show up</p>
  
  <blockquote>
    <p>You can manually start the scan by going to <strong>Tools > Script Manager...</strong> and clicking the <strong>Reload</strong> button.</p>
  </blockquote>
  
  <p>However, no such menu item exists.</p>
  
  <p><img src="https://i.stack.imgur.com/Mz2Y9.png" alt="Tools drop down, no &quot;Script Manager&quot;"></p>
  
  <p>Just cut off in that screenshot is a "Script Center Menu", which has just one option for "Read Data". It's unclear what that does. It's also unclear how the "Script Editor" ends up tying back into the existing spreadsheet to become available...</p>
  
  <p>Does anyone know the current steps required to write a simple google script function and then access it from within a Google spreadsheet?</p>