Sendit: https://pikidiary.lol/users/sendit | Allows anonymous posts to be sent.
Pikidiary Status (DISCONTINUED): https://blips.club/pikidiarystatus | A fan account for posting the status of Pikidiary.
PikiDownage: https://wish13yt.github.io/PikiDownage/ | A tool that lets you check the status of Pikidiary.
PikiBrowse: https://github.com/wish13yt/pikibrowse | A tool for viewing Pikidiary via Python.
Bioring: https://bioring.pages.dev/ | A fun webring for Pikidiary!
RingGen: https://bioring.wishdog.link/ | A BioRing generator!
If you have any more ideas, let me know by making an issue!