There is some argument about terminology, whether the notion of blockchain includes the peer-to-peer distribution and consensus mechanism (eg proof-of-work) or not. (In my view, it shouldn't.)
Git uses a somewhat extended version of a blockchain (a directed acyclic graph instead of just a linked list).
I think it's a cool technology, and has many applications where you want an immutable sequence of records. But it's not a panacea, and the current hype is overblown.
I've been messing around with using a blockchain for storing DNS records, I think it's a neat idea, but the overhead is pretty large considering the small amount of data that is involved.
Close to cryptocurrency, but reward points seem like a good use case. That is, something very seamless to move rewards around whether they were earned for a hotel, airline, credit card, etc. Points.com takes a pretty big cut for that (centralized) service today.
Money transfer as well, maybe. I don't know the space well, but it seems like MoneyGram, Western Union, and similar charge a high premium for their services in some cases.
Stellar Lumens is one of the top coins working on remittances, IBM is partnered with them. It's also a non-profit. Highly recommend doing some research into this one.
Luxury handbags? Check the blockchain to confirm it is real.
Need goods transported at a consistent temperature? The blockchain can validate that your shipment did in fact remain (or not) at a certain temperature.
Want to buy a scalped ticket? Scan the QR code and confirm the ticket is usable.
Use of clearing for financial markets. You'll be able to verify that party A has the instrument and party B has the currency without needing to go through a separate company.
Git uses a somewhat extended version of a blockchain (a directed acyclic graph instead of just a linked list).
I think it's a cool technology, and has many applications where you want an immutable sequence of records. But it's not a panacea, and the current hype is overblown.