A team of Twitter alumni is today launching a new consumer social app,, aimed at helping people share their personal recommendations of places to visit — like restaurants, bars, museums, and other businesses, even trails and parks. Using a combination of AI and computer vision technologies, the app aims to make it easier to get started sharing your recommendations by scouring your phone’s Camera Roll for photos from favorite spots, which you can then add to curated playlists that are shared with friends and followers.
Founded in 2021 by former Twitter product manager, who previously led the initiative to change Twitter’s character limit from 140 to 280, Rex has been in active development for a little over a year and a half. Today, the app is officially exiting beta testing and being made available to the public.
The startup is also announcing its raise of $3.96 million in seed funding from Accel, Khosla Ventures, and other investors from Twitter, Snap, and Pinterest, including Twitter co-founder Biz Stone, via his fund.
Rosen says she was inspired to build a social recommendations app because she’s always been interested in trip planning, even as a kid.
“I just loved the process of thinking about new places to go — whether that was a far-off destination or in the city that I lived in and the surrounding area,” the founder explains. “I’ve always just been super fascinated with discovering new places,” she says, but notes that it’s often difficult to actually do the research to discover the best spots.
“Finding places for any given circumstance that meets our needs and preferences can be really hard…this is the experience I’ve faced,” Rosen continues. “The internet is just inundated with reviews, ratings, recommendations, and blog posts from strangers whose tastes we don’t know.” Plus, she adds, the crowdsourced model of apps like TripAdvisor and Yelp now feels antiquated compared to the social products people use today that deliver personalized, curated content in an efficient way.
Those pain points led to the development of Rex — an app that aims to tackle the problems associated both with discovering new places and sharing your own recommendations with others.
Using Rex is as simple as the startup promises. You walk through a few initial steps to provide Rex with permission to access your contacts and photos on your phone and then its technology begins working to discover what possible recommendations may already be hidden away in your Camera Roll.
Rosen assures us that the team is taking steps to ensure the app still respects users’ privacy when doing so, however.
“I have two privacy engineers on my team who came from 1Password and they are obsessed with security,” she notes. The company doesn’t store users’ photos on its own servers — it’s only storing the metadata locally on users’ devices. Only when a user chooses to make a recommendation is the data then stored on Rex’s servers, Rosen notes.
To determine what recommendations you may have to share, Rex has developed a proprietary ML model trained on computer vision of images. The model looks for images of places, specifically, and matches that with photo metadata to determine if the place may be something worth sharing — like a photo of a dish at a restaurant, for example. It’s also looking at other signals, like the coordinates of the photo and timestamps, then tries to put together a best guess as to when that picture was taken.
When you find a photo that represents a place you’d like to recommend, it’s only a couple of taps to share it with your friends. You check a box, enter some text about why your want to recommend the place, and publish. The spot can be added to “playlists” you curate, as well — like those for your hometown or other cities you’ve visited, or by other themes, like cuisine. These “rex” are also published to a global feed where you can see the recommendations from others.
Your friends’ ongoing recommendations are available in a global feed, but what’s most helpful is the app’s map view which lets you actually explore your friends’ recommendations around you. That way, when you’re visiting a new city or even your own, you can scan to see what places nearby your friends have suggested are worth the visit.
“In a world where we’re inundated with one-size-fits-all content, blogs, and lists, Rex delivers signal amidst all the noise by helping us discover places and experiences validated by people we already trust,” said Rex backer, Amit Kumar of Accel, in a statement. “Mining the camera roll turns out to be a particularly smart way to do this; it already contains an extremely reliable signal of where we go and what places we like. No one else in the space has attempted anything like it, meaning no recommendations are quite as curated or personal as Rex.”
Rex is a. The app is not yet generating revenue through ads, subscriptions, or in-app purchases.