Every few months, I report bugs in the mobile library's filter function. I can't remember which ones of them I've already reported, but I can remember that these have been in existence for a very, very long time with no development TLC sent their way. I suspect that these are all related to one another.
The current bug o' th' month is this:
Filters can be applied in two ways in the mobile app. You can type them yourself or you can select items in from the "Filters" dropdown. If I type the filter myself, I can avoid looking through my very long list of user tags (or authors or series or whatever). The problem is that the filter mechanism fails if I try to apply more than one type of filter. (Another bug, but that was from another month.) So I can use the "Filters" dropdown. Here, I can look for the "USER TAGS" I've applied to my library. ("USER TAGS are what the desktop more consistently calls "My Tags". This terminology is also suggested when I start typing my filter by hand in the mobile app with "m", and a "mytag:" pops up automatically. I don't know why the mobile app calls them "USER TAGS". That's another bug.) In this case, I have a number of tags that begin with "FBOM" for various avenues of the awesome "Free book of the month" offerings. E.g., I have some that are "FBOM Subscription", "FBOM Verbum", etc. But I also have "FBOM" from tags I applied a long time ago when I had no reason to distinguish. According to the documentation (at least in the WIKI), putting this parameter in quotes should limit my filter to books with the FBOM tag only, but it doesn't work that way (another bug).
So if I look at the Filters dropdown, I can see the explicit "FBOM" tag and it counts 45 of them. Cool. That's actually how many that I have. However—and here's the actual bug I want to report this month—when I select "FBOM" from this list and apply the filter to my library, it reveals 72 books that qualify. I understand why the 72 books show up (namely, because the filter doesn't actually work), but it's odd that the filter is inconsistently applied.
