Pretty much anybody who follows the instructions in this video can create a delayed appearance button or form in just a few minutes following this video.
If you have any questions or problems put them in the comments and I'll answer them!
[NOTE TO MODS: No links or mentions of any of my websites in the video. If there's a problem in any way with the content, let me know and I will change it.]
I added another option with a slightly different code that allows you to show a button for a certain amount of time rather than keeping it visible forever. To avoid confusion I put the attachment and instructions in a response. You can see it here:
The text file in the video is below: