I've released three libraries for Kotlin/Java:
A simple implementation of the URL shortening (bitlinks) abilities of the Bitly v4 API.
bitly.bitlinks().shorten("https://www.example.com/")
A simple implementation of the is.gd API for URL shortening.
Isgd.shorten("https://www.example.com/")
A pretty complete and straightforward implementation of the Automattic's Akismet API, a free service which can be used to actively stop comments spam.
val akismet = Akismet(apiKey = "API_KEY", blog = "https://www.example.com/")
val comment = AkismetComment(request = context.getRequest())
val isSpam = akismet.checkComment(comment)