This is a good program, one of the best I’ve seen to organize your collection. That said, the database appears to be based on everyone else’s entries, and that can lead to significant discrepancies.
For instance, scanning the UPC for The Avengers #43 (June, 2021) will return “Avengers (2018) #43”. Scanning issue #44 will return “Avengers (Vol. 8) #44. Since your collection is sorted by title, then date, the different titles make it extremely difficult to determine which issues you have (and which ones you need). Additionally, the primary covers cannot be changed if you want to use an existing entry, so if you don’t like the photo, or if it’s wrong (as it has been more than a few times), you will have to enter everything manually.
Lastly, you can’t enter an entire series, like Secret Wars #1-12 or Camelot 3000 #1-12, and will have to enter each issue. If you have a large collection with pre-2000 issues, prepare to do a lot of manual entries.
Don’t get me wrong, once you get everything in and it the right order it’s great, but getting there should be much easier.