Jupiter Ace port of Dave Stepenson's Tut-Tut. That's been good for testing the hardware along the way.
May the 4th be with you.
2022 Update: Yes, I did go to the effort of launching the Minstrel 4th on May the 4th so I could do that joke. We did a run of Minstrel 4th Final Edition kits last year, and they all sold out quite quickly. It is unlikely there will be any more. At the time of writing, there are still a few Minstrel 2 (ZX80) and Minstrel 3 (ZX81) kits available from The Future Was 8 bit
2023 Update, Now, of course, there is the Minstrel 4D, available in kit and built form. Shipping now from The Future Was 8 bit.
More info in a previous post:
You can support me via Patreon, and get access to advance previews of posts like this and behind the scenes updates. These are often in more detail than I can fit in here, and some of these posts contain bits from several Patreon posts. This also includes access to my Patreon only Discord server for even more regular updates.