After a day spent listening to pitches at Y Combinator Demo Day, it’s hard not to be impressed. Young entrepreneurs from around the world brought their passion and vitality to Silicon Valley to make a mark on the world, and their ideas will touch many millions of lives. Y Combinator companies are chosen both on the basis of the idea, and the backgrounds and potential of the founding team, which is what must make the selection process both challeng

Picking favorites is no easy task, with so many brilliant ideas being packed into a few short hours.

Fortunately Y Combinator made the process a little easier for us because so many of the companies presenting were listed as “off the record.” We’re still trying to figure out exactly what it means, but for various reasons–either because of institutional capacity reasons, or user perception–it’s now seen as better for certain early stage companies not to advertise their connection to the Y Combinator program. Of the 62 startups who presented, 30 were off the record. Several of the companies were happy to talk with us on the record, as long as we don’t mention the Y Combinator connection, until it’s sanctioned. We’ll gladly oblige, and we look forward to sharing their concepts with the audience of The Next Web. If you’re really sharp, you may be able to figure out who is who on your own.

To narrow down our favorites, we looked at four factors: potential impact/disruptive capability, mobile experience/ease of mobile demo, design, and raw innovation.

Potential Impact/ Disruptive Capability

Aisle50

More than $35 billion is spent annually to market groceries in free-standing inserts, the coupon mailers that almost no one reads. Migrating coupons to people’s smart phones makes a lot of sense, but could make a lot more in cash.

MixRank

Mixrank provides competitive intelligence for online advertising. Spy on your competitors’ ad campaigns, track what works, and react swiftly. Pretty scary to think that a rival is using it, and you’re not.

Quartzy

Quartzy organizes the $9 billion spent annually on products for scientific research labs, with an intuitive online tool. Helping to manage inventory and relationships with vendors of life sciences equipment and chemicals eliminates a major headache, but the planned addition of “buy now” button will unleash of river of revenue.

Science Exchange

Who knew that much of the life-saving medicine and scientific breakthroughs we rely upon depends upon outsourced research. We didn’t it turns out that 20 percent of private research is outsourced, and the total market is in the neighborhood of $76 billion annually. Science Exchange is going after a $4 billion piece of the action, and with a team that can’t be beat.

Debteye

Debteye makes debt relief simple and easy to navigate in the same way that Turbotax makes it possible with taxes. Debteye brings together a team that understands how to manage the consumer debt process, with capable programmers who love solving code problems. Debteye is one of our favorite startups from the most recent Y Combinator batch, and they also have the distinction of being our favorite demo slide of the day too.

Easy to Demo on a Mobile Device

Launchpad Toys

Launchpad toys brings to the iPad the best of the Web for children’s learning that leaves kids empowered and inspired to create and share their ideas. The intuitive interface is one of the best out there for the iPad, and shows just how much can be done with touch screens, and how much remains to be seen.

Paperlinks

We see QR codes popping up just about everywhere, but what good are they really doing? With Paperlinks businesses can unleash the power of this emerging smart phone technology infrastructure, even going so far as to sell coffee on billboards that can be picked up at a nearby cafe.

Tagstand

This technology could go into several categories, as a disruptor, or an easy-to-demo mobile concept. Simply put, the Tagstand near field communication technology stores data that can be unlocked with a simple bump. Co-founder Tulveer Taggar tapped his phone against a sticker on the wall and it started to play a song. Billions of phones will be equipped with NFC technology in the oncoming years, and Tagstand wants to power them all.

Vimessa

With Vimessa you can send video messages with the ease of sending an SMS. Asynchronous communication takes a massive leap forward, as video clips are stored in the cloud and downloaded to your phone or device when you’re ready. Video messages will capture the emotion of any moment with a video clip that puts your viewer right there.
Verbling

When in the process of learning a language, perhaps the most difficult aspect is being able to retain what you’ve learned. For most of us, the problem here is our inability to practice these newly-digested phrases on a regular basis — it just doesn’t stick without constant use. Verbling solves this issue by providing a platform where language learners can connect with native speakers for verbal practice in-browser with real-time and live video. Co-Founder Mikael Bernstein (a former military interrogator fluent in 4 different languages) explained that distribution for the service would not be a problem as Verbling is inherently social with over 18,000 users having signed up within the first month of launch.

Cool concepts/gorgeous designs

Market Brief

Have you ever found yourself zoning out while trying to digest a massive list of statistics and data? For reporters especially, the task of breaking down information into a readable piece that everyone can understand is a mind-numbing process. With Market Brief, however, this task can be handled in only 1 second. MarketBrief takes SEC filings and puts these through a system of humans and computers to create an easy to understand article containing all of the important information you’ll need.

Opez

Of the many startups we had the pleasure of viewing during YC Demo Day, Opez was probably one of our top favorites. Opez markets themselves as “Yelp for individual service professionals.” What does that mean? People like your favorite bartender at the local watering hole or that amazing taxi cab driver you always go to can now receive personal reviews from you and your friends. Opez claims to be “inherently viral” as service professionals using the platform are now using Opez in their resumes, telling their friends to rate them, and passing on the service to those who can benefit from the new rating platform.

Codecademy

Gamification for coding? We’re all over it! Just like those typing games you may have played online that improve both your speed and accuracy, Codecademy hopes to make coding easier for beginners looking to learn the basics of coding. With an interactive and fun service that you can use alongside your friends, Codecademy has already managed to acquire over 250,000 users in only 4 days since launch. In fact, Codecademy users are averaging at least 1 hour in the program during each use. Advertisers are already looking to market through the service, while the founders promise 100x more content in the future than what is already available.

Gorgeous Designs

Snapjoy

Co-Founders Michael Dwan and JP Ren of Snapjoy are aiming for the big boys when it comes to photo storage. “Snapjoy is going to be the place where you will keep all of your photos,” says Dwan during his Y Combinator presentation. Unlike Flickr, Facebook, etc, Snapjoy allows you to upload your photos in full to the cloud without compressing or modifying your files. Over 1.8 million photos have already been uploaded to the platform, while the intuitive service uses an AI system that automatically organizes your photos into separate events for you. Photos are made easy with Snapjoy.

Kicksend

Oh, Kicksend. When even our tech-challenged moms can use your realtime file sharing and delivery service, we know we have a winner. Through Kicksend’s easy-to-understand UI and user friendly application, sharing files is as easy as dragging and dropping into the platform for sharing in a snap. You can even organize your friends and family into groups to share with multiple friends at once.

Can’t Wait

Can’t Wait is “movies made social”. By targeting users who only have enough time to watch quick movie trailers on the go, Can’t Wait is able to track which movies consumers want to see, then quickly notifies the user through Push Notifications to purchase an early ticket through the system. Currently only available via iPhone and in-browser, they next plan to release on Android while keeping an eye out on the tablet market. The ability to share movie trailers with your friends is another great feature the platform provides, and even rewards users for sharing by helping them score free movie tickets redeemable for whatever they want to see in theaters.

Raw Innovation

Envolve

With Envolve’s scalable real-time chat on your website, users are proven to spend 4X the amount of time that they do on your page than they would without it. Community sites like Destructoid are already using Envolve, with an average of over 300,000 messages a day being sent through the channel. The ability to create individual user accounts and customize the look and feel of your Envolve chat box with simple tools and flexible API are what make the extra social channel so easy to integrate onto your domain while complimenting the look and feel of your current layout.

Vidyard

When it comes to videos for businesses, Vidyard believes that YouTube is the “dead end of the internet”. Publishing your company’s video to YouTube won’t guarantee that your product or service will receive the attention it deserves as these videos are listed alongside competitors or even regularly “trolled” by the YouTube community. This startup hopes to provide a more professional hosting platform for businesses to upload their videos where they can receive real analytics and embedding tools along with links back through optimized SEO.

Bushido

Promising to get “all the apps, all the data, and all the users,” Bushido is a hosted ecosystem and app store for developers. Bushido is a self-contained ecosystem for Ruby on Rails app developers that speeds deployment and makes launching new features easy, and creates powerful channels of communication between users and developer communities.