Just one thing, browsing by topic doesn't seem to have any sort of rhyme or reason in its ordering aside from some vague first-letter ordering. For example, there are numerous "I" categories, with one "I" for "interactive" and another one for "Interactive". One grouping of "I"'s includes tags "ios", "iOS", and "ip", but the next "I" grouping below just contains "IP"
Edit: I see the ordering issue now. There's a list of topics. The list is printed out in alphabetical order. But for some reason when the first letter of a topic changes between capital letter and a lowercase letter, a new letter grouping is created. Probably it's creating a new category whenever the first character changes, but it did not take into account capital and lowercase characters being different.