One person, one TikTok account, prices from six supermarkets: how the Chilean price-comparison app Piya climbed to #4 on the overall free chart

Piya is a supermarket price-comparison app built by an indie developer in Chile: scan a barcode and it tells you what the same item costs at six chain supermarkets. Chile already had seven or eight tools like this, and none of them took off. What's different about Piya isn't the product. It's that, six weeks before launch, it started posting short videos every day on "same item, how much more it costs at a different supermarket." One month after launch, riding a few viral videos, it twice broke into the top 20 on the Chilean App Store's free overall chart, reaching #4 on Nov 4. The playbook could transfer to other countries and categories, but only if you're willing to post videos every day.

Oct 22, a "street interview" in front of supermarket shelves

Oct 22, @piya.cl posted a 30-second vertical video. In front of a supermarket shelf, a person holds up a phone and scans a product. An off-camera voice asks: "Hi, sorry to bother you, what are you doing?" She says: "I'm scanning products. I want to buy this, but it seems other supermarkets are cheaper. I use an app that tells me where's cheapest." Then she demonstrates: scan the barcode, and prices from other supermarkets pop up. "What's it called?" "Piya." "Where do I get it?" "The App Store."

This video got 84k views and 744 shares (TikTok, 11-06). Five days later, on Oct 27, another video comparing one shopping list across several supermarkets reached 236k views, 10k likes and 2,231 shares. The top-liked comment in the thread was "To get things cheap you have to go through every supermarket and only buy the specials" (907 likes); the next was "I've never seen Tottus's Pillows cereal at that price." The next day, Piya hit #16 on Chile's free overall chart and #2 on the Shopping free chart.

What it is

The first line of the store page is "Stop overpaying at the supermarket." The features are straightforward:

• Scan a barcode or search, and see the price of the same item at six stores (Líder, Jumbo, Tottus, Unimarc, Santa Isabel, Alvi), sorted from cheapest to most expensive;
• See price history to judge whether to buy today;
• Build a shopping list and calculate which store is cheapest for the whole basket;
• Chilean food packaging carries the mandatory black "ALTO EN" (high in sugar, salt or fat) warning label. Piya shows this too, and you can filter by preferences like gluten-free or vegetarian;
• Later it added "prices after card or loyalty-club discounts," a map of nearby supermarkets, and travel times.

The developer account is in the name of Cristian Vergara, and he has only this one app under it. Launched on Oct 5, iOS only.

Why now: six weeks of warming up the account, then riding a government news story

Piya's TikTok account started posting on Aug 25, six weeks before the app launched. Most of those videos got only a few hundred to a few thousand views, and each one invited viewers to sign up for early access at piya.cl.

The turning point was Sep 7. That day, Chile's consumer protection agency SERNAC published its price comparison of the national holiday shopping list (Sep 18): the same basket of barbecue ingredients for 4 people cost as little as $23.139 pesos at the cheapest store and as much as $78.197 at the most expensive, a gap of nearly 55k pesos, and the price gap had widened 2025% from 83.9 years earlier. Piya turned the story into a video that same day, with the caption: "Same basket, nearly $55.000 apart. The issue isn't how much you'll spend for the holiday, it's how much you're overpaying without realizing it. That's why we built PIYA." The video got 163k views and was the only hit before launch.

On Oct 4 it posted "Available on the App Store tomorrow," and the waitlist converted directly after launch. From Oct 21 onward, the videos kept hitting: 10-22 84k, 10-25 106k, 10-27 236k. On Nov 3, a "new version" video got 88k views, and the next day Piya climbed to #4 on Chile's free overall chart and #1 on the Shopping free chart.

The rankings jumped up in steps and fell whenever the videos stopped. It's worth knowing: the Chilean market is small, so #4 on the free overall chart probably means only a few thousand downloads a day (my estimate).

Where users come from

Almost all of it came from TikTok. A five-star App Store review says it plainly: "I found Piya on TikTok and didn't really believe it, until I did this month's shopping and saved nearly 30k pesos compared to last month." (App Store Chile, 11-02)

The brand account @piya.cl had only 4,303 followers and 49 videos as of 11-06. It grew by individual videos breaking out, not by follower count. The video formats are few: "street interview"-style demos in front of shelves, one shopping list compared store by store, price-gap stories riding government news, and a "new feature" video with each update.

A few accounts are very likely helping promote it, but I can't confirm it. @datosdelsuper's bio reads "Real supermarket prices in Chile." Two of its videos at the end of August got about 250k views each, using hashtags nearly identical to @piya.cl's. @esevergaraaa has "vergara" in its username and also posts supermarket price comparisons, with two videos at 189k and 278k views. The founder describes himself on Instagram as "all about AI, apps, viral marketing... founder of @piya.cl." That these two are his own alt accounts is my inference.

There's also a mom-savings account with 2,500 followers that takes partnerships, which promoted it once at the end of September, on a very small scale. On Instagram it used "comment PIYA and we'll DM you the download link." I found no press coverage and no evidence of paid advertising (not finding it doesn't mean it didn't happen).

Where the money comes from

The free version allows 3 scans a day. To scan more, you need the Premium subscription: $4.990 pesos a month (about 5 USD) or $34.990 pesos a year, with a 7-day trial on the annual plan. Premium sells unlimited scans, price-drop alerts and "how much you've actually saved."

There's definitely some money coming in: it has steadily ranked #5 to #11 on Chile's Shopping grossing chart. But that chart has a very low bar. On the same day, the #1 package-tracking app had only 131 ratings in total, so #5 only shows that some people are paying, not how much. Revenue has never been made public.

Reviews are mixed on paying. The positive ones say "The Premium money is covered by what you save" and "This app pays for itself." The complaints are "One supermarket trip means scanning more than 3 items, and paying this early is discouraging" (3 stars) and "You have to subscribe to use it, it's not free" (1 star).

Who it's competing with

The last line says it best: the same product is built in three countries, and the ones without content never took off.

Its weak spot shows in the comments too. The most common TikTok questions are "When is the Android version coming?" and "iPhone only?". Someone says "Prices are off, I can't even find this item on the supermarket website." One-star App Store reviews say "The product catalog won't load, I tried several searches and nothing comes up." Prices are scraped from supermarket websites, and online prices don't always match in-store prices. If a supermarket blocks the scraping one day, the product stops.

If it were you

Bottom line: Worth following. The barrier to this business isn't the tech, it's distribution. Copying Piya's playbook of "build a following with price-gap videos first, then launch" into a country where nobody has done it yet is well timed right now.

Who it suits: People who can write a scraper and reliably pull prices from a few chain supermarket sites, and who will post a short video every day in the local accent (or have a partner who can be on camera).

Who it doesn't suit: People who want to build the product but won't show their face or edit videos. Chile has seven or eight price-comparison sites, and the same app exists in three countries. Building one that nobody uses is normal for this category.

How to do it:

• Pick a country where a few chains dominate, online prices are public, and the consumer agency or government regularly publishes price comparison reports. Peru, Colombia and Mexico are worth a look. Argentina and Spain already have clone apps, but none of them do content, so there's still room.
• It doesn't have to be supermarkets. Pharmacies, gas stations, baby products and pet food all work, as long as it's the same item costing much more at one store than another.
• The minimum viable version is three things: scan a barcode, sort prices from several stores low to high, and show which store is cheapest for the whole basket. Give free scans for a few uses, then sell a subscription for unlimited scans and price-drop alerts. Giving only 3 scans is clearly too few, and reviewers have complained about it.
• There's also a local gap in Chile: Android. Piya only built for iOS, and comments ask for Android every day.

How to get users:

• Open the account 4 to 6 weeks before launch, post every day, and push a waitlist sign-up.
• Stick to a few video formats: street interviews of people scanning at the shelf, one shopping list compared across several stores, and "guess which store is cheapest".
• Watch the consumer agency and government price reports, and film the same day one drops.
• Post a "new feature" video with every update. You can run two or three unbranded "supermarket savings tests" accounts and push them together with the same hashtags.

Best timing: Launching and warming up accounts before the Christmas and New Year shopping season (December) is ideal, since that's when people care most about supermarket spending. The days the consumer agency publishes price reports ahead of national holidays are your best shot at a viral video.

What would mean you read it wrong:

• If three or four videos in a row don't reach 10K views, or the app doesn't move downloads even at 10K+, the audience in that country isn't buying the format.
• If the conversion from free to paid is so low that the app can't even reach the top-grossing chart, the model isn't working.
• Supermarkets start blocking scrapers, or online and in-store prices drift too far apart and reviews fill up with "wrong prices".