The week the top app went down, a hand-drawn cat caught its users: Japanese barometric app 「ゆる気圧」

In Japan there's a group of people who get headaches the day before rain, and their phones all have a barometric forecast app called 「頭痛ーる」. In late October 2026, the app went down for nearly a week. A user of more than ten years had just launched their own replacement three days earlier, with a hand-drawn cat that comforts you. Below: how it got seen, why it keeps people, whether the playbook can be copied, and why we think following it directly isn't worth much.

A post tagged with the rival's outage

In late October 22, an account called @yurukiatsu posted on Threads:

I built a weather-pressure app called 【ゆる気圧】! I've been using 頭痛ーる for 16 years, but I wanted an app that shows no ads, feels soothing, and lets you say when it's rough. A cat does the soothing. It walks across the graph. It's free.

("I made a barometric app. I've used 頭痛ーる for 16 years, and I wanted an app with no ads at first, that heals you, and that lets you say 'this is awful.' A cat heals you. It walks on the graph. It's free.")

The post ended with two tags: #頭痛ーる #頭痛ーるメンテナンス (頭痛ーる under maintenance). The post got 13k views and 261 likes (Threads, 11-06 views).

That was right when Zutsuuru (頭痛ーる) went down. Its official account posted an apology on Oct 23: "Service has been unavailable for an extended period...", and temporarily pointed users to a weather-pressure forecast page elsewhere. The restoration was only announced on Oct 27. By Oct 22 people were already posting on X: "Zutsuuru under maintenance, can't use it." Zutsuuru is the category leader: 71K ratings on the Japan App Store, and it sits at #3–4 on the Free chart in Weather year-round, with about 1.2M MAU (per its partner weather account's bio).

Over a million people a day suddenly couldn't open the thing they relied on, so they went looking for replacements. Those searching the outage tag came across a post saying "I'm a 16-year user too, so I made one."

The maker is Miki Murayama, who goes by 「あおい」, an indie developer whose only App Store app this is. Her pinned Oct 20 post is more direct: she was going to build a third app for something else, but the pressure kept making her miserable, so she built this one first. "Ads keep increasing, I want to see the graph, but it's exhausting."

What it actually is

Opening it shows a pressure curve with a cat for today on it (later a Shiba named 「こむぎ」 was added). When pressure drops, the cat slides down the curve like a slide. Below it, 「いま、どう?」 asks how you're doing. Tap 「だいじょうぶ / まあまあ / つらい」 and the cat replies with a line.

The features are standard for this category, and the data comes from Apple Weather, same as everyone else's: barometric pressure from the past 12 hours to the next 48 hours, five status levels, and an alert about 3 hours before pressure drops. What it adds is a fix for a few complaints from long-time users:

• Ads are a single thin banner that "doesn't block the chart." The creator's explanation: 「Appleに場所代12800円払っているので」 ("I'm paying Apple 12,800 yen in 'rent'").
• Alerts also fire when pressure rises, with a 「びんかん」 (sensitive) mode. No pushes overnight.
• No sign-up. Your health data stays on the phone, and location isn't stored.
• The store page includes a promise: 「『頑張って』とは言いません」, meaning it won't tell you to "hang in there."

Paid is a subscription at ¥200/month or ¥1,600/year (per the store page).

Users stay because of the cat

Japan App Store: 11-06:4.69 stars from 39 ratings. Almost every review is the same word: 「癒される」 ("healing"):

When I'm not feeling well, just watching the cat and Shiba heals me. I feel the same way, it says, and the warm, gentle companionship helps. I forget the pressure part (lol) and keep looking at the cat and Shiba. (4 stars, 11-01)

I've used other apps for years, but with more ads I tried this one... I look forward to new friends joining. (5 stars, 11-03)

Falling pressure is exhausting, but watching the cat slide down like a slide is healing. (5 stars, 11-02)

The second one is exactly a 頭痛ーる defector. Another 10-25 review states the source outright: "I read the developer's posts on Threads and downloaded it."

"New friends" refers to the creator's preview of more cat breeds and companions. For a tool app, having a reason to "wait for the next character" is its second retention hook.

How big the numbers are

Small, but the fastest among the new entrants in its cohort.

(Japan App Store, checked once a day. There's no record before 10-28, so how high it climbed during the outage week isn't visible.)

After 10-28 it added 0–5 ratings a day, 17 in a week. For comparison, the pressure newcomers launched in the same 2026 year, 「みあケア」 (March) and 「ズツノート」 (June), had almost zero new ratings in the same period.

On 11-06 it hit #11 on the chart. Three things collided that day: version 1.4.0 added English and launched in the US, Canada, UK and Australia; Japan had a dramatic pressure swing that week (頭痛ーる's official account was also posting 「気圧急上昇」 alerts); and the creator posted a companion post about "this week's intense pressure." Which one did the work can't be separated. It's not on the Top Grossing chart, so revenue is probably small (inference).

Separately, on Oct 26 a large English account, @berrily.app, posted a roundup titled "small apps that deserve way more downloads" with 400k views, and the creator thanked them in the replies. At that time the app was only in Japanese, so how many downloads that post drove can't be verified. But it's likely why she later made an English version and opened @yurukiatsu.en separately (inference).

Who it's competing with

Barometric headache apps are a crowded category in Japan. More than 60 apps on the Japan App Store have 「気圧」 or 「頭痛」 in the name. More than 2026 of the indie products launched in the past 30 years have fewer than 10 ratings.

The last line matters most. The "character + low pressure" idea had at least two other apps before it, both with zero ratings. The idea isn't scarce; being seen is. ゆる気圧 won on two things: hand-drawn art and copy good enough to keep people, and saying one line at the right moment, with the right identity and the right tag, to bring people in.

How many people know about it

Almost nobody. No media coverage, no discussion on X about 「ゆる気圧」 in nearly 30 days, and the creator's Threads account has fewer than 300 followers. We found no trace of paid ads or TikTok. We also haven't seen a clear copycat yet. 「ねこもよう - 猫と天気」, launched 11-02, is a cat plus weather, not a barometric-illness app.

If it were you

One-line verdict: worth learning from, not worth copying. It took off because of the week 頭痛ーる went down, and that window has closed. The Japan barometric category has already taken in 30+ new entrants this year, and the two closest to it have zero ratings. Subscription at ¥200/month caps the scale. What you can really take away is two moves: "post on the day the top player fails, as an ex-user, with the event tag," and "give a tool you check daily, and that annoys you when you do, a layer of a character that comforts you."

Who it suits: indie developers who are long-term users of some chronic discomfort themselves, who can draw or find an illustration style that stays consistent, and who post in a real voice on places like Threads, Instagram or Xiaohongshu, where many women users are.

Who it doesn't suit: people who want to build another barometric app in Japan (too crowded, and you don't have that week). People who expect to make money from it (¥200/month subscription, and it hasn't even reached the Top Grossing chart). People who can code but can't draw or write gentle copy. The moat of this product is the art and the words.

How to do it: Keep the form, change the scenario. Pick something people check every day that makes them miserable: pollen (Japan's spring season), periods and PMS, insomnia, air quality. Pull from free sources (Apple Weather, public pollen and air data). The home screen shows a character, not charts. A daily check-in gets one line back, and never "you've got this." Release characters in batches. Or switch languages: 11-06 has only just entered the English-speaking market, and the existing English pressure apps are mostly pure utilities (Barometric Pressure Tracker and the like). A pressure app with a comforting cat hasn't been done well in English yet (my inference, not systematically verified).

How to get users: two things. Day to day: post companion content on a schedule tied to the forecast ("pressure's wild this week, hang in there, everyone"), using patient tags (in Japanese, tags like #気圧のせい). At key moments: list the top apps in your scenario and watch them for outages, price hikes, added ads, and bad reviews after redesigns. On the day something breaks, post as "I'm an old user too," and include their event tag. The 13k-view post for ゆる気圧 came about exactly this way.

When it needs to be ready by: the pollen direction needs to launch before the end of January 2027, since Japan's pollen season starts in February. Other directions have no hard deadline, but should be ready before the next time the top app you're watching goes down.

What would show we misread it: ① ゆる気圧's English version gets hundreds of ratings in the US store within a month or two. That would mean the language-switch path is wider than we think, and it should be upgraded. ② The reverse: its Japan rating growth falls to single digits a week or less, and it drops out of the top 50 in the weather chart. That would mean the outage wave was the whole story, and the character's word of mouth can't sustain organic growth. ③ 頭痛ーる releases an ad-free version or adds its own character companionship. That would mean the leader has filled the gap, and this path narrows.