Amazing! Looking forward to testing this out. It does say that I need an email link or an invite code before I can use it, so let us know what that is.
I was able to add it through TestFlight from the link you sent above.
Just a couple of quick notes from using it very briefly:
I was confused by having to go to the settings page to search for a device to pre-fill it on the Add device page. A search of template selection on the add device page would be more intuitive, I think. The current process seems to be: go to the settings page (which was also a bit hard to find), then searching by the model, then clicking on it in the search results, then closing the settings, then clicking add device. That seems like a lot of unnecessary steps when the main time someone will be using that is when adding a new device, so I'd think it would be better on the add device page.
I think some improvements to the search may be needed. For example, if I search for "SE", the Macintosh SE/30 is the only model in the SE lineup that shows up in the search results. I know it's because the string "se" appears in so many device names (Macintosh Mou
se), but maybe prioritize the beginning of the string higher than a substring of the name.
When on the device list, it took me too long (I'm embarrassed to admit how long it took me) to figure out how to view the device details after adding it. I'd prefer if clicking anywhere on the list item brought up the device details.
Additionally, while the photos capability it functional, I prefer to see thumbnails of the device photos that I can click on to see in more details. Having it open a finder window with the copied files is less ideal.
I also think I found a bug. I was trying to add a second device and when I go to the Add device form and hit "Save", the dialog goes away and it doesn't add a device.
I think this app looks really great from a design perspective. I love the look and the concept, and I don't think it will work for my requirements, I bet it will help a lot of people who want a much easier to install, simple to use system for keeping track of their collections.
[EDIT] With respect to the "bug" I thought I found, I figured it was a user problem, however one that maybe you could think about from a UX perspective. The reason I thought the save wasn't working is because I had entered text in the search field. The device I added didn't match the search field. So after I realized that and cleared the search field text, I could see the 3 devices I had added repeatedly thinking they didn't save. Something users might only do once, but it was a "is the app not working?" moment for me. You might consider clearing the search field if a user adds a new device. Or maybe make the face that results are filtered a bit more prominent. Also, providing a temporary indication that the device was added successfully could be all the feedback needed.
[EDIT 2] Question: what drives the categorization of the listings. I thought maybe it was by the type attribute on the device, but it does not seem to be. The last two devices I added (An Apple Lisa) and a Studio Display, both now show up on my list under "Accessories". I also just added a PowerMac G3 All-in-One (I just discovered if you enter the model number it pre-fills the form on the Add Device page. Maybe add some messaging around that field that it will help pre-fill if you have the model number). All my new devices are now getting added under the Accessories grouping and I can't figure out what drives that.