HK Blood is a free mobile application developed by the Hong Kong Red Cross Blood Transfusion Service. The app aims to make blood donation more accessible and user-friendly for Hong Kong citizens. It offers a range of features such as looking up donation history, booking appointments for whole blood donation, searching for donation centers, and self-evaluating eligibility before blood donation.

The app also encourages users to invite others to donate blood, share their donation achievements on social media, and collect and exchange blood type characters to build their own virtual village. HK Blood sends push notifications for the latest news and promotions, making it easier for users to stay updated. Overall, the app is a useful tool for those who want to donate blood in Hong Kong and also want to keep track of their donation history and progress.