At Y Combinator, founders decide when they want to announce that they’re part of the program. Meet 12 of the companies who have announced that they’re part of the YC Winter 2018 batch so far:

Buglife is a mobile SDK and web platform for reporting bugs and collecting feedback in mobile apps. The founders came up with the idea while working on Amazon’s first music app. Jeff Bezos would email bugs to their team with minimal detail, so they had to build tools to capture diagnostic data from his phone. Buglife is currently used in 300+ apps. Their customers include Coinbase, Instacart, Cabify, and it’s even used in IoT devices like the June oven. Read more about Buglife in TechCrunch.

Cognition IP is a tech-enabled law firm that helps companies with patent law. They are developing AI that will make patent drafting and litigation dramatically more efficient. This lets them offer extremely fast service and flat-fee pricing that’s 2-4x lower than most large law firms. The strategy of building a law firm that is vertically integrated with a legal tech company gives Cognition IP an advantage over existing law firms and other legal tech startups alike. Unlike most legal tech startups that sell tools that address only part of a legal process, Cognition IP can solve legal problems end-to-end with services provided by its lawyers. Just two weeks into the YC program, Cognition IP was serving 10% of the startups in the batch, and they have many clients from prior YC batches as well. Read more about Cognition IP in TechCrunch.

Juni Learning offers live, online computer science classes for kids ages 8-18 with a private instructor. They’re applying the VIPKID model, which has worked well in China for language learning, to computer science. To date, Juni has taught thousands of classes to students in the US, China, and five other countries. The founders of Juni Learning, Vivian Shen and Ruby Lee, are computer science grads from Stanford. Read more about Juni Learning in TechCrunch.

Medumo prepares patients for hospital visits and surgeries. By tracking and A/B testing patient behavior at scale, Medumo’s software predicts/prevents failure by optimizing and customizing patient instructions. 12 hospital systems have used Medumo to reduce their cancellations by over 50%, and increase operational efficiency and patient satisfaction. Read more about Medumo in TechCrunch.

Nutrigene sends you personalized, liquid vitamin supplements that work 10x better than powder-based pills. You pick a goal (optimize gut health, get essentials, or improve performance), and they send liquid supplements that are built for you, based on scientific research. The company is founded by behavioral scientist and holistic health coach Min FitzGerald and Dr. Van Duesterberg, biophysicist and epigeneticist. Read more about Nutrigene in TechCrunch.

Sheerly Genius is the company behind the world’s first pair of indestructible sheer pantyhose. Rip-proof, snag-proof, life-proof. Made with the same type of fiber found in bullet-proof vests, Sheerly Genius pantyhose have been tested up to 50 wears. Read more about Sheerly Genius in TechCrunch.

Slite is building the first notes app designed for teams. It’s like Evernote + Slack, and we believe it could kill internal wikis and replace tools like Google Docs and Confluence. They’re already building a product people love — they already have over 150 teams using the app and more than 2,500 weekly users. Read more about Slite in TechCrunch.

Statecraft is using data to help cities address the most critical housing challenges. They track planning approval times, identify major bottlenecks, measure how much space is left, and evaluate the impact of affordable housing policies. Statecraft can help governments understand which cities have the most effective policies and provide them with benchmarks and best practices. Read more about Statecraft in Government Technology.

Storyline makes it easy for anyone to create Amazon Alexa skills without coding. They’re building Weebly for voice apps. Their target customers are brands, companies and individuals who want to engage customers on emerging voice platforms like Alexa and Google Home. Smart speakers sales grew 300% in 2017, and 39 million Americans now own a smart speaker device. Today, most companies don’t have Alexa skills, or they are very basic. Storyline makes building advanced skills easy. So far, there are over 110,000 unique users of skills that were built on Storyline. Read more about Storyline in TechCrunch.

Substack makes it simple for a writer to start a paid or free newsletter. Writers get a CMS purpose-built for publishing email newsletters, integrated payments through Stripe, and a website that can host free and subscriber-only content. Read more about Substack in Fortune.

tEQuitable is building a 3rd party Ombuds platform to address issues of bias, discrimination and harassment in the workplace. tEQuitable’s team is uniquely qualified to build this platform — founder Lisa Gelobter has worked as a product expert across tech, entertainment and government, CTO Heidi Williams has been developing enterprise tech for 20 years and Freada Kapor Klein is the foremost expert on harassment in the workplace. Read more about tEQuitable in the Washington Post.

The Lobby lets candidates buy affordable 1-on-1 calls with company insiders to help them land top finance jobs without needing an inside connection. It’s become clear that if you don’t come from a privileged background or elite school, there’s a ceiling on the career opportunities available to you. Most job candidates need connections and insights from insiders to break into top industries, and The Lobby hopes to help democratize access to those resources. The Lobby’s private beta has over 100 insiders across the top 15 large and boutique investment banks. ~40% of their paying users getting employee referrals after each call. Read more about The Lobby in VentureBeat.