These applications would not be particularly well suited for blockchain technology:

• Digital Identity
• Data management between organizations
• Patient chart
• IoT

The above would be better suited to use cryptography technology. There is little advantage to using blockchain technology for any of the above, because once an entity has access to the information, they can trivially replicate it in unencrypted format.

Supply chain and real estate might be two good useful applications for blockchain technology, especially the later. Real estate becomes tricky when liens are involved because a lien can result in ownership being unilaterally being transferred, and liens can sometimes be put in via judicial action. Parcels can also be split up, which would be difficult to account for with blockchain technology. It would also be a problem when private keys are lost and/or stolen.

Supply chains using blockchain technology would rely on the trust that private keys are not being sold/transferred among market participants. A good use for this would be to trace the history of diamonds to ensure a particular diamond is not a "blood diamond", however if private keys are being transferred, those trafficking blood diamonds might be able to launder diamonds into the supply chain.