What it is: An online store that sells its own "brandless" goods — everything from salsa to toilet paper — for $3 an item.
Brandless, which launched in July, can sell its products cheaper than those carrying household names because it doesn't have to charge the kind of "brand tax" that comes with those products, company founders Ido Leffler and Tina Sharkey told Business Insider. As its name implies, the company sells its products online in simple packaging that's similar to that of the generic products found in grocery stores.
The company is counting on Millennials to make it a success. Leffler and Sharkey think they'll appreciate Brandless' ability to combine the convenience of online shopping with low, flat prices. Indeed, they think its one-price model should help it stand out from Amazon, Jet.com, and other big online retailers, many of which adjust prices their prices frequently.
Funding: $50 million from investors including Cowboy Ventures, Redpoint Ventures, and Google Ventures, according to Crunchbase.
The most successful roll-out: LimeBike
What it is: A bike-sharing network that places bicycles where commuters need them.
Following the lead of efforts including New York's Citi Bike and San Francisco's Ford GoBikes, LimeBike combines a convenient app with well-placed two-wheelers to handle what's known as the "first and last-mile problem" — getting commuters to and from public transportation hubs.
The company got its first round of funding in March and has now raised $62 million. Its $225 million valuation makes LimeBike one of the most valuable companies to launch in 2017.
Funding: $62 million total from investors including Andreessen Horowitz and IDG Capital, according to PitchBook.
A standout product in a saturated market: Obsidian Security
What it is: A cybersecurity company that focuses on a particular niche — hybrid clouds.
Increasingly popular among enterprise companies, hybrid cloud systems allow those companies' in-house servers to interoperate with public cloud systems, such as those offered by Amazon and Google. Obsidian uses artificial intelligence and machine learning to provide security across these complex, hybrid systems.
It takes a lot to stand out in the cybersecurity market, but Obsidian has an all-star cast that's warmed investors to its potential. CEO Glenn Chisholm worked at the antivirus software company Cylance as its chief technology officer. CTO Ben Johnson previously founded another cybersecurity company, Carbon Black.
Obsidian's most recent funding round valued the company at $27 million, according to PitchBook.
Funding: $9.5 million in a series A led by Greylock Partners, according to Pitchbook.
The highest valued: Devoted Health
What it is: A venture-backed insurance company that plans to offer Medicare Advantage plans to seniors starting in 2019.
Healthcare was one of the hottest markets for venture capital investments in 2017, and Devoted Health is a leader of the pack. Founded by alumni of AthenaHealth — a publicly traded healthcare tech company — Devoted Health is working on using technology to help seniors navigate the medical system.
Devoted Health raised its first round of funding in May and ended the year as the most valuable US startup that launched in 2017. The company has a valuation of $295 million, according to PitchBook.
Funding: $67.41 million led by Oak HC/FT and Venrock, according to Pitchbook.
The most likely to make your life easier: Socrates AI
What it is: Socrates AI has developed an artificial intelligence technology that's designed to help employees navigate all aspects of their companies' human resources departments and systems, from benefits questions to paperwork.
Its Socrates virtual assistant works with companies' existing systems and allows employees to talk with a chatbot or send a text instead of having to manage multiple logins or programs. It's designed to offer a more natural and seamless experience than most employees experience today when navigating office bureaucracies.
The company raised its first funding round in January, and is now valued at $44 million.
Funding: $16 million led by Venrock.
A startup model for the future: Orchid Labs
What it is: Orchid Labs is developing technology that's designed to allow users to access the internet free from surveillance or censorship.
Its system is based in part on blockchain technology, the digital ledger system that underlies cryptocurrencies including bitcoin. But it's not just its product that makes Orchid Labs such a hot startup. The company is also a pioneer in a new kind of venture capital fundraising process called a Simple Agreement for Future Tokens, or SAFT.
In a SAFT, venture capitalists invest a certain amount of money in a startup in exchange for its promise to one day give them a set amount of its cyber tokens when it holds an initial coin offering. SAFT's are premised on the notion that once a company's service is up and running and customers are using its tokens to pay for things on it, those tokens will become valuable.
Orchid Labs, which raised its seed round in October, is one of the first blockchain-based companies to work with venture capitalists using this funding technique. Its success could set the tone for how such deals go in the future.
Funding: $4.7 million from investors including Andreessen Horowitz and Sequoia Capital.
The most high-profile founder: Essential
What it is:A consumer gadget company founded by Andy Rubin — the guy who created Google's Android.
Rubin intended Essential to be a smaller, more nimble competitor to Apple, Samsung, and other giant electronics companies. Its initial product, the Essential Phone, was one of the first to sport a large, nearly borderless screen, and it features a magnetic connector that allows users to easily connect accessories. After working on the phone in stealth for years, Rubin unveiled it in May.
Funding: $330 million total, with its most recent round led by Access Technology Ventures, according to Crunchbase.
Bonus — the most addictive: HQ Trivia
What it is: This one comes with a big asterisk. While HQ Trivia launched this year, it's an app not a startup, and its parent company, Intermedia Labs, actually dates to 2016.
If you're not yet in on the craze, HQ Trivia is an addictive smartphone trivia game. It's focused on a live contest that happens twice a day. Its hundreds of thousands of players compete for cash prizes.
Developed by Vine founders Rus Yusupov and Colin Kroll, HQ Trivia went live in August and steadily picked up steam during the fall. It reached a new high during the holidays — the 730,000 players on Christmas Day were an all-time record for the company.