Some Potential blockchain implementation and replacement of current product/service.

Akasha (https://akasha.world)

Similar service: Facebook, Twitter

As a decentralized application AKASHA deploys a next-generation information architecture born from the fusion of Ethereum and the Inter-Planetary File System. Thanks to these technologies we were able to create a planetary-scale information network immune to censorship by design, where your thoughts and ideas will echo throughout humanity’s existence.

LBRY (https://lbry.io)

Similar service: iTunes, Bandcamp, 500px, kindle books

LBRY is a free, open, and community-run digital marketplace.
You own your data. You control the network. Indeed, you are the network.
Hollywood films, college lessons, amazing streamers and more are on the first media network ruled by you.

MysteriumNetwork (https://mysterium.network)

Similar service: VPN provider

Decentralized VPNpowered by Blockchain
Open Sourced Network allowing anyone to rent their unused Network traffic, while providing a secure connection for those in need.

Maidsafe (https://maidsafe.net)

Similar service: Freenet, zeronet

The SAFE (Secure Access For Everyone) Network is made up of the unused hard drive space, processing power and data connection of its users. It offers a level of security and privacy not currently available on the existing Internet and turns the tables on companies, putting users in control of their data, rather than trusting it to organisations.

Aragon (https://aragon.one)

Similar service: ERP products?

Aragon lets you manage entire organizations using the blockchain. This makes Aragon organizations more efficient than their traditional counterparties.
By making it possible for everyone in the world to organize, we are enabling the borderless, permissionless creation of value.

Lunyr (https://lunyr.com)

Similar service: Wikipedia

Lunyr is an Ethereum-based decentralized world knowledge base which rewards users with app tokens for peer-reviewing and contributing information. We aim to be the starting point of the internet for finding reliable, accurate information. Our long-term vision is to develop a knowledge base API that developers can use to create next generation decentralized applications in Artificial Intelligence, Virtual Reality, Augmented Reality, and more.

Steem (https://steem.io)

Competitor: Blog, News

Steem is a blockchain-based social media platform where anyone can earn rewards.