Hi Usc1,
I created the app, and I use the checklist for my personal collection. It's pretty much no frills. You check the items that you have, and then you can view them in a custom gallery. Here's a quick demo video:
https://www.dropbox.com/s/usx5xudzd3...-Demo.MP4?dl=0
I really do need to update the store listings to include a similar video.
Thank you for your interest,
-Trae