# Manage your health with GP-Online > Source: > Published: 2026-05-23 22:49:40+00:00 !This is a submission for the Gemma 4 Challenge: Build with Gemma 4 Healthcare is one of the largest consumers of SaaS products, comprising roughly 15%–18% of the overall global SaaS market and growing at a CAGR of 15%–20%. Despite the abundance of software, most of it targets high-volume paying customers through complex enterprise information systems (60%–70%), leaving a significant market gap for patient-facing or GP-facing tools. This issue is acutely felt in Europe, where health SaaS adoption sits at approximately 18% — and significantly lower in central and eastern Europe. Booking a GP appointment is a prime example. Many patients in Bulgaria resort to calling the doctor personally to arrange a visit, while a single GP can manage upwards of 2,000 patients. I wanted to simplify this process by building a web app that syncs with patient and doctor calendars and offers a seamless, real-time booking option. The app was built in English for the purposes of the competition. https://youtu.be/EaOodungK8g GitHub Repository — ktashkov-jpg/gp-online-en I used Google AI Studio with the Gemma model for the full experience. The initial prompt was designed around three constraints: the app targets the Bulgarian healthcare market, GPs are listed in a public registry with open Swagger documentation, and since calendar syncing requires OAuth, a demo mode should be available for immediate testing without setup. I need an app which would allow patients to easily book appointments with their general practitioners (GPs) in Bulgaria. These practitioners often have more than a thousand patients, sometimes up to 2,000. The app should sync with Google Calendar, Outlook Calendar, or any other native calendar. When an appointment is booked, the app should check real-time availability and alert both patient and doctor. Every Sunday, the app should notify the doctor about upcoming appointments and reasons (e.g. "Monday: 3 appointments"). Consider adding a mock patient/doctor for dashboard inspection.