PERIOD. is the EU-built cycle tracking app. An AI assistant trained on women's health — PMS, PCOS, PMDD, contraception, cycle nutrition. No ads. No data resale. Free forever for the basics. Plus (€3.49/mo) unlocks unlimited AI. Bootstrapped in Amsterdam. Servers in Ireland, no US subprocessors for user data. #1 period tracker in the Netherlands with 30,000 active users and ~150 organic signups a day. The privacy-first alternative to Flo and Clue.