Bitcoin's advocates argue that the underlying "blockchain" technology extends far beyond currency alone. One example, Edgelogic, wants to stamp out diamond thieves. It does this by registering the precious stones on a public ledger called Blocktrace. Bitcoin's blockchain technology distributes the record of all transactions using the digital currency between users on the network (meaning they can't be later changed to defraud users). Similarly, Edgelogic's Blocktrace will share the details of valuables on the network, making it harder to fence stolen goods or commit insurance fraud.
Retailer adoption is still a major hurdle facing Bitcoin: In the real world, there are very few shops that are able to accept the digital currency. While companies like Coinbase and Blockchain are building merchant tools to make this easier, Blade has a workaround in the interim. It offers a pre-paid debit card that users can top up with Bitcoin, and then use anywhere that accepts cards. It means crypto aficionados can continue to "pay with Bitcoin" even in shops that have never heard of digital currencies.
CoinDesk reports that the CEO, Ed Boyle, previously served as general manager for American Express' prepaid cards unit.
23. Coinapult: Pegging Bitcoin to commodity prices
Bitcoin may be exciting, it may be innovative, but it's not exactly stable. In January 2015, its value plummeted by 30% in a matter of days, having already declined all year from its giddy highs of $1,000+ at the start of 2014.
Coinapult offers a solution for those who want to hold Bitcoin but worry about the price risk with a service called LOCKS. Launched in July 2014, it lets users pegs their Bitcoin to the value of a variety of commodities, including the US dollar, British pounds, gold, and silver.
So if the user bought $10-worth of Bitcoin, then the price doubled overnight, they would continue to hold $10-worth of Bitcoin at the new price. It means they don't profit off the price rise — but they're also inured to a potential dropoff.
Founded in 2011, Coinapult is based in Panama City.
22. BitPesa: Remittances to Africa
BitPesa is a Kenya-based remittance service promising to help customers "send money to Africa — cheaper and faster." Charging a 3% transfer fee, they convert the sender's Bitcoin into shillings and distribute it to your chosen recipient.
21. Ledger Wallet: A physical Bitcoin wallet for your pocket
Ledger Wallet exists for people who like a bit of physicality to their cash.
Bitcoin "wallets" that store the digital currency are, at their simplest, nothing but a public and private key: Two strings of characters that can be used to receive and transmit Bitcoin. You can save them however you like, or even write them down on paper. But Ledger Wallet offers a more comprehensive option. It's a kind of customised USB stick holding your wallet, boasting "state of the art security" and claiming to be "malware proof." It also plans to introduce NFC for easier payments.
Ripple is an alternative cryptocurrency based on Bitcoin. It's the second-largest digital currency in market cap, and aims to solve many of the problems Bitcoin faces — like the time it takes to verify transactions. It doesn't bother with "mining" either, the process by which new Bitcoin are "discovered" by users in return for contributing computing power to the network's upkeep. All the coins are "pre-mined." It's particularly useful for transferring money which can then be turned back into a local currency: "the coins are largely perfunctory for users simply looking to use the network to send payments," Rob Wile wrote. "They're basically just temporary vehicles for your fiat."
Based in the UK, Elliptic offers top-of-the-line Bitcoin storage to keep your digital coins safe. Not only has it obtained "ISAE 3402 accreditation" from KPMG — "a global standard for financial reporting," CoinDesk reports, it also insures the Bitcoin it holds. This means if it's ever hacked (a not-uncommon occurrence in the Bitcoin ecosystem), you're not going to lose any funds as a result.
17. Coinalytics: Analytics for the Bitcoin economy
Because the blockchain ledger of Bitcoin transactions is public, there's an immense amount of data out there waiting to be mined. Coinalytics wants to find data in this noise, which can provide actionable guidance for Bitcoin enthusiasts. CoinDesk describes the company's mission as "building the Bloomberg for Bitcoin."
Circle's secret, according to then-Forbes writer Kashmir Hill, is "not telling people they're using Bitcoin." Acknowledging the fact that many consumers don't want to use Bitcoin per se — they just want easy-to-use and robust financial products — Circle helps people store funds and transfer cash simply, prominently displaying the dollar-value of their balance. It also mimics "some of the traditional deposit-providing and custodial features of traditional banks," according to the Wall Street Journal, and it insures funds held on the platform.
15. Factom: Using the Blockchain as an all-purpose record-keeper
Factom wants to utilise the blockchain — the distributed ledger that powers Bitcoin — as a tool for decentralised record-keeping, ensuring the integrity of data stored remains intact without having to rely on any one single bookkeeper.
Property titles are one item that could be stored on the blockchain's "immutable ledger," Factom suggests, or audits, or (presumably encrypted) medical records.
14. World Passport: A store for identity documents
Once something is written to the blockchain, it's there for good. It takes a "51% attack" — where one rogue actor controls more than half of the entire network — to undo it. It's this decentralised strength that ensures the integrity of the Bitcoin network.
Chris Ellis is a crypto enthusiast excited about the technology's capacity for record-keeping. He has dreamt up World Passport, a project to store identity documents along the blockchain. It means anyone can prove who they say they are, without having to rely on the authority of a nation-state. The integrity of the network is enough. "I wanted to create a voluntary ID system in which my proof of existence could be backed by a social network of my choosing," he told Wired.
13. ChromaWay (and coloured coins): A new way to represent physical assets
The term "coloured coins" refers to an additional layer built on top of the Bitcoin network that uses existing bitcoin to signify other — potentially physical — assets, expanding its use beyond simple currency. CoinDesk's Danny Bradbury explains the concept well:
Bitcoins are useful, but like dollars or euros they are only used as currency. Coloured coins look to change this by using bitcoins to represent other things. ‘Colouring’ a bitcoin means attaching a piece of information to it, which turns it into a token for something else.
For example, what if transactions in the bitcoin block chain could be used to represent, say, company stock, gold or a deed to a building? Then, someone could issue shares on the bitcoin network, or trade commodities on it.
This would give bitcoins a huge advantage over traditional ways of sending assets. If you want to send gold, company stock, or the physical deeds to a house today, this necessitates a complicated process involving notaries, registered deliveries and paper trails.
The coloured coin is still very much in its infancy, but there are multiple projects underway. ChromaWay and Colu are among the attempts to bring coloured coins to a broader audience.
12. Blockchain: The best tool for exploring the blockchain
Founded in 2011 by Ben Reeves, Blockchain (the company) offers users an easy way to explore the blockchain (the technology), such as a tool to let shopkeepers accept Bitcoin. Instead of a central bank auditing transactions, Bitcoin relies on a distributed network shared between its users — everyone holds a public ledger of every transaction carried out using Bitcoin, which are then checked against one another to ensure accuracy. This ledger is called the blockchain, and Blockchain (with a capital B) lets users examine it and follow the flow of any Bitcoin.
In addition to this explorer, they also offer a wallet service for holding users' Bitcoins. In October 2014, it raised $30 million in venture capital funding, then the largest-ever for a Bitcoin company, and it's currently seeing between 20,000 and 30,000 new sign-ups for its services every week.
Filecoin is a digital currency with a novel twist. The integrity of the Bitcoin network is maintained by users contributing processing power to its upkeep, and are then rewarded accordingly with the currency. In contrast, Filecoin asks its users to contribute storage space, for which they are then rewarded. This storage can then be purchased — turning the entire network into a massive decentralised cloud storage repository for people's files.
Bitcoin is anonymous, but it isn't untraceable. The public nature of the blockchain ledger of transactions means you can trace any coin through the network indefinitely. Once you know who owns a certain wallet, it's trivial to monitor how much of the digital currency they hold in that wallet at any given time, and exactly which wallets they're sending it to (if not who actually owns those wallets).
DarkWallet is an answer to this: It mixes users' coins together, making them effectively untraceable. It's a kind of high-tech money-laundering.
There's obvious potential for abuse by criminals and terrorists, but this doesn't faze developer Amir Taaki. In an interview with the BBC, he acknowledged that it could be utilised by ISIS, but argued that "you can't stop using technology because of your personal bias. We stand for free and open systems where anybody can participate, no matter who you are."
It exemplifies the ultra-libertarian, political streak that drives many in the cryptocurrency movement — people who believes the technology is not just a new currency, it's the potential for a whole new social order. Perhaps appropriately, Taaki lives in an anarchist squat.
9. Blockstream: Linking other alt-currencies to Bitcoin
Bitcoin isn't the only digital currency. There are also numerous other "altcoins" ("alternative coins") using some variation on blockchain technology, from Litecoin to Dogecoin — but none of these have ever got as much traction as Bitcoin. Blockstream wants to tap into the specialised benefits that these altcoins offer, without rejecting Bitcoin altogether.
It does this with "side-chains" that can be pegged to the Bitcoin blockchain. "For all intents and purposes, side-chains would effectively be new blockchains that are backed by Bitcoin," explains Silicon Angle, "in much the same way that fiat currencies used to be backed by gold." Assets could then be transferred across the two blockchains when required.
Swarm is, at its simplest, a crowdfunding startup. It lets the public chip in and help fund various projects — a Kickstarter for Bitcoin. But it's also far more than that. As a part of a push towards "distributed governance," it explores ideas of decentralisation and new ways companies and even governments can operate, empowered by the way Bitcoin does away with any one central authority.
"The vision is to restore to all people the power currently monopolised by the one percent — the power to participate meaningful in public life," says co-founder Joel Dietz.
One of its most exciting aspects has nothing to do with crowdfunding. The startup is looking into using Bitcoin's blockchain ledger to help facilitate voting. In a world first, the Bitcoin Foundation (a digital currency advocacy group) held elections last month using Swarm's technology to let people vote on new board members using Bitcoin, "[providing] ever greater transparency into the voting process."
7. Gemini: Fully regulated Bitcoin exchange
Olympic rowers-turned-tech entrepreneurs Tyler and Cameron Winklevoss claim to own at least 1% of all Bitcoin in existence. But they're not prepared to sit on their spoils: The Harvard-educated twins are currently gearing up to launch Gemini early this year.
It will be be a fully-regulated, US-based Bitcoin exchange where individuals and institutions can buy and sell the digital currency. The twins describe it as the "Nasdaq of Bitcoin," and will open its doors as soon as it has the necessary regulatory approvals.
6. BitPagos: Solving real-world currency instability in developing countries
Most Bitcoin merchant tools are designed to help shopkeepers and retailers to accept the digital currency, before transferring it — if required — into fiat currency. But BitPagos turns this on its head, and allows merchants to accept fiat currencies which are then converted into Bitcoin before being added to their wallets.
Bitcoin is often touted as a boon to people in the developing world, where mature financial tools are not yet widely available. BitPagos is one of these, and offers a degree of stability to citizens of countries where the price of Bitcoin may actually fluctuate less than the local currency (as well as avoiding exorbitant card fees). It's something CEO Sebastian Serrano knows all about — he is originally from Argentina, and has lived through bouts of extreme economic instability in the country.
The only startup on this list not directly using blockchain technology, CoinDesk nonetheless firmly deserves its spot in the top 5. It is a cryptocurrency-focused news site, and since its launch in May 2013, it has grown to become one of the largest and best-respected sources of information about the industry.
ChangeTip is a "love button for the Internet." Fees in the established financial industry can make tipping small amounts impractical, but Bitcoin has no such barriers. (There are still some fees incurred when transferring Bitcoin, but they are comparatively tiny.)
As such, ChangeTip lets users on Reddit and other social media sites "tip" others using simple commands. You can specify an amount, or use of of the pre-determined commands: "beer" is $3.50, for example, a "donut" is $0.35, and a "burrito" is $5.75. It's a way to reward good quality content or contributions. What's particularly exciting about ChangeTip is that while many Bitcoin initiatives are years away from maturity, it's already having a huge impact, powering a vibrant tipping culture in cryptocurrency-focused communities like Reddit.
The exchange isn't its only project, however. It also offers wallets that let users store their Bitcoins, as well as merchant payment systems to help businesses accept the digital currency.
Founded in 2012 by Brian Armstrong, now the CEO, and Fred Ehrsam, it has its headquarters in San Francisco.
2. Ethereum (and Counterparty): Autonomous, decentralised app distribution
Ethereum is the most prominent of the "Bitcoin 2.0" projects taking blockchain technology beyond the confines of currency. It wants to use the technology to build decentralised applications that can run autonomously. The fact that these applications will run on the blockchain rather than any single computer will make it far more difficult — if not impossible — to shut them down.
1. 21: "Core infrastructure for mainstreaming bitcoin"
What is 21? Outside of a chosen few, no-one knows for sure. But that hasn't stopped it raising a staggering $116 million before it has even launched — a record for the industry.
It's led by VC Balaji Srinivasan, who is a partner at venture capital firm Andreessen Horowitz — which was one of the firms to invest in 21's recent round, along with RRE Ventures. When the news of its funding round broke, CEO/co-founder Matthew Pauker told the Wall Street Journal that it was working on "several interesting developments over the next weeks and months" that will help "drive mainstream adoption of Bitcoin."
Highly respected VC Marc Andreessen said 21 "is working on what they — and we — consider to be core infrastructure for mainstreaming bitcoin."
Hardware manufacturer Qualcomm (who also works with Apple and Samsung) is involved, and many believe 21 intends to embed the Bitcoin network into consumer electronics and the coming "Internet of things." 5 years from now your smartphone, your router, your laptop and your fridge may all be part of the Bitcoin network, if 21 gets its way.