If you want to know to whom you can give blood or from whom you can receive blood, then this is the right app for you. Just supply the app with your blood group and the app will tell you to which blood group you can give and receive blood from.
Note: All apps published by me are free and always will be. The permissions required for the apps are merely for the integrated ads that support me build such apps. I guarantee you that none will harm your device, so please feel free to install and try them out. Thanks.