MedDroid is a free AI Health OS for patients, families, clinics and hospitals. Patients get an AI assistant that explains lab reports, prescriptions, X-rays and scans in plain words in 30+ languages, by text, voice or WhatsApp; a health timeline with vitals, alerts, dose reminders and 18 free health apps; and video calls with verified doctors. Clinics and hospitals get 14 free systems (EMR, e-prescribing, decision support, lab, radiology and PACS, pharmacy, billing and claims, appointments, teleconsultation, hospital wards, ERP) plus an AI receptionist, in a desktop app for Windows, macOS and Linux. MedDroid Sync OS runs on the clinic's own computer: records stay encrypted on site and AI works offline. Also included: FHIR and SMART on FHIR, ABDM/ABHA, an MCP server for Claude, ChatGPT and Gemini, and a marketplace of free apps and models. General health information, not a diagnosis.