Wearable ECG monitor in a form of a smart t-shirt, capable of collecting the ECG recordings, determining the level of stress and fatigue of the body with a further cloud AI-based diagnostics. It is able to monitor a heart function remotely, during different life cycles and detect heart-related problems faster than in a clinic. HeartIn offers two products: fitness wearable for sport lovers and trainers and medical solution for hospitals and patients. HeartIn Fit combines medical grade monitoring with professional workout features. HeartIn ECG collects the data, recorded by textile electrodes and send it to the app where it is being analyzed by the AI algorithm. It informs the user when to start, when to rest, how to train with the maximum utility and the lowest harm for a heart.