I believe it starts with education and exposure. The earlier we can start teaching children about different communities, volunteering, mentoring, social responsibility and the like, the easier it is to ingrain in them the importance of engaging with other demographics. It would be great if schools built in a formal program in the curriculum and sponsored programs which encouraged interaction between youth and seniors. The activities would vary to keep the young engaged and enable seniors to feel supported in different settings.
I'm wondering what the barriers to blood donations are currently (e.g. stigma associated with blood donation, lack of awareness or education about blood donations, access to medical facilities etc.) and whether you've done research in this area to understand how you may address these issues. In Australia, stringent eligibility criteria deems many people ineligible to donate. There are also many campaigns to raise awareness and encourage donations but there always seems to be a shortage. I think this would need to be address before the APP would even be applicable.