Blood donor search applications are online platforms or mobile apps that allow individuals in need of a blood transfusion to locate and connect with potential donors in their area. The main purpose of a blood donor search application is to connect individuals in need of blood with individuals who are willing and able to donate blood. This can be especially useful in emergency situations where time is the essence, and it is important to quickly locate a suitable donor. The Haversine algorithm can be used to calculate the distance between the location of an individual in need of a blood transfusion and the location of potential donors. This information can then be used to identify the nearest potential blood donors and connect them with the individual in need. Cloud-based services can prove to be important in emergency blood delivery since they enable central and immediate access to donors’ data and location from anywhere. React Native is used to build user interface and handle the user interactions, Firebase is used to store information about blood donors and for cloud messaging, Express and Node.js are used in conjunction to build the backend server and API and Google Maps API is used to display maps and location information.