Thanks to +Tony T for the heads up.
Link to the post at 5e Spellbook Generator
Here's the text in full:
Dear Fellow RPG fans,
Thank you guys for supporting my work and spreading it out through the multiverse. I am glad it has gotten enough attention to have finally garnered a cease order from Wizards of the Coast.
Unfortunately, I would not like to make any real legal trouble to myself, so I have taken down the spellbook generator as it is. I will be providing (give me a week or so) the code as open source, not including any database with the spell information. If at any time, the Wizards decides to release an OGL for 5e, I will be more than happy to bring this back online.
I am really touched by how many people have sent me inquiries already about the spellbook generator. If you guys would like to continue to support the right and need for players to have tools such as this, feel free to email Wizards of the Coast and voice your concerns! As a DM and a player I wanted a tool in which to help my group out and together, a ton of you guys came and made that dream come true. As much as I understand why I was served a cease order, I am also saddened at the need for it. This generator did not help you play the game at all, it just made it so that you as a player could easily go through the beautiful content Wizards has provided. You still needed a PHB to play, so you've already given Wizards your money.
Good luck to all you gamers out there. This will not be the last you have heard of the spellbook generator! For other resources, feel free to check the about page. Use them until Wizards takes them down too!
*UPDATE* - Open source code available here.
NOTE TO WIZARDS - I am only open sourcing the code that I have written and own. I will not be distributing any underlying database or datasource containing the spell information to populate the application.