3.Titra

3.Titra is the kind of niche app that flies under the radar until you actually need it — and then you can't believe nothing like it existed before. It tracks GLP-1 meds like Ozempic and Wegovy, but the pharmacokinetic serum level visualization is what makes it actually useful rather than just another logging app, since you can see estimated drug concentrations over time instead of just checking boxes. The fact that it's free, ad-free, and available in 24 languages with almost 3.5 minutes of average engagement tells me the founders actually use their own product, which is honestly rare in health tech right now. It's not huge yet at 4.5K users, but the specificity here is the signal — this is built for people who want real data to show their doctor, not just another wellness app.