Getting an iPhone "family registry": a free tool from a Xiamen team, and how it hit #1 on the Korean utilities chart

FoxPeek (called "小狐探机" in China) does something simple: it reads the diagnostic file the iPhone generates itself, tells you which company made the screen, memory, storage, battery, and cameras, and grades each part. When the iPhone 18 panel and the foldable iPhone Duo launched in Korea, Korean users called the report "아이폰 등본" (iPhone family registry). At the end of October, it climbed from #133 to #1 on Korea's free utilities chart within a week.

An iPhone Duo "family registry"

On Oct 23, the iPhone Duo went on sale in Korea. Quality complaints about the inner screen and hinge started almost right away, and Samsung even ran an ad mocking it (both 주간경향 10-29 and YTN 10-31 covered it). Just in the last few days, someone checked their Duo with FoxPeek and posted a screenshot: display from Samsung, memory from Samsung, flash storage from SK Hynix, front and ultrawide cameras from LG.

From Oct 31 to Nov 1, at least three Korean Instagram meme accounts posted this same image almost at once, with similar captions: 짤퀸, 유머꿀꿀, 유머만해. All three tagged the app's name. The comments started riffing: 「한국계 미국인」 (Korean-American), 'Sperm and eggs are both made in Korea.'

The chart moves line up: on the Korean Tools Top Free chart, it was #30 on Oct 133,31 daily #18, then #2 on Nov 1, and #5 on the overall Top Free chart on Nov 10 (App Store Korea).

What it is

iPhone already logs a lot of diagnostic information. You can find the Analytics file under Settings > Privacy & Security > Analytics & Improvements > Analytics Data, or capture a sysdiagnose with a key combo. It holds part codes like panel serial numbers and storage chip models. For example, panel serial prefixes G9N mean Samsung, GVC means LG, and JLN means BOE. Ordinary people can't read them.

FoxPeek lets you import that file. It translates the codes into manufacturer names, grades each part as "Top / Good / Standard," and produces a report you can screenshot and share. It also has battery cycle count and health, plus small tools for dead pixels and storage speed.

It's completely free, with no in-app purchases or ads on the store page. The developer is Xiamen Infinity Starway Technology, which also publishes free tools like 万能指令, 全能实况, 悬浮时间 and 充电功率助手, each with thousands to tens of thousands of ratings in the China store. FoxPeek launched in July and added Korean and Japanese by late July. In Sep 30 it added support for iPhone 18 Pro, and in Oct 25 the 1.4.1 version added iPhone Duo support. It keeps up within days of every new phone launch.

The need was already there. It just added three things.

In Korea, checking whose panel you got is nothing new. Since the iPhone 17 generation, clien, Naver blogs and tistory have carried plenty of tutorials on using 3 uTools (爱思助手) over USB or digging through logs and matching them against code tables. Apple's built-in "Parts and Service History" only tells you whether a part is genuine, not who made it.

China has similar apps too. 「系统电池分析 SystemBatteryAnalysis」 launched in September 2025. It also imports the Analytics file, has 15k ratings in the China store, and reached #6 on the China Tools Top Free chart in Nov 4. But it focuses on battery health, has no Korean, and has only 3 ratings in the Korean store.

FoxPeek differs in three ways:

• Everything runs on the phone, no computer needed.
• It grades each part and turns the result into a card. Got a Samsung panel? Post it. Got a BOE panel? Complain and go for a refund. The card is what users share.
• It added Korean early. The biggest comparable app skipped Korea, and FoxPeek took that open slot.

Where users come from

The spread came through screenshots shared in communities. I found no evidence of paid acquisition. The app is free with no in-app purchases, so there's no path where paid acquisition pays back.

• Late September, Threads in Taiwan and Hong Kong. When the iPhone 18 launched, lots of people posted "小狐探機" reports and asked Meta AI to interpret them. Meta AI's reply said: "This is the 小狐探機 spec lookup report everyone has been sharing lately." One post saying "download 小狐探機" (9-28) got 11k views. Volume wasn't big, though: Taiwan and Hong Kong only had about 50-60 ratings each.
• Early October, Korea's DC iPhone Gallery (iPhone board). People were arguing about the iPhone 18 Pro specs. On Oct 4 a post titled "Foxpeek 바이럴이냐?" (Is Foxpeek viral marketing?) said: "18 series specs are being fought over hard, everyone is using this to check specs, and more people are posting their results to prove it." The nickname "户口本" (household registry) came out of this period. On Oct 9 a five-star review said: "아이폰 등본 떼기 좋음" (Good for pulling your iPhone's household registry).
• Late October, iPhone Duo and the "Korean parts" topic. This was the meme wave from the opening. On TikTok on Nov 3 a post read "iPhone Duo didn't even copy the answers, proof #Samsung #LG #SKhynix" and got only 391 views. The main battlefield was Instagram and communities.
• After it charted. Being #1 on the Tools chart brought in another group of users from the chart and search (inferred).

On the numbers: Korea store ratings in Oct 31 were 42, Nov 6 were 165, 7 days added 124, and Nov 6 alone added 32 (App Store Korea, 11-06). The Korean utility category has a low bar for charting and a low rating rate, so actual downloads are probably about an order of magnitude above the rating count (inference, unverified).

Is someone pushing it behind the scenes? Korean users are suspicious themselves. Besides the "바이럴이냐" post, a one-star review on Nov 1 said: "This is a Chinese app. You hand it a file with a unique identifier, are you crazy? If you came here from Threads or DC communities, go learn what viral marketing is first." Three meme accounts posted on the same day with nearly identical structure, which looks like a coordinated push, or just the usual habit of Korean meme accounts reposting hot threads. Neither claim can be confirmed.

Where the money comes from

We can't see that. It's a tool you use once and leave, so it doesn't rely on retention. It may be driving traffic to the developer's other big China-store tools, it may be building a user base before charging, or it may treat diagnostic data (model, parts, serial numbers) as an asset. The last one is speculation. The privacy policy says data is "processed on the device by default," and the declared data type is only "Performance Data."

How many people know about it now

Not many. No media coverage, nobody has mentioned it on X in the past two months, and no public revenue figures. It circulated for a while only in Korean DC, clien, Instagram meme accounts and Taiwan Threads circles, and it came with the "Chinese app takes your serial number" criticism. Since November I haven't seen any new Korean-language comparable apps.

Heat is fading: on the overall Top Free chart it was #5 on Nov 10,6 and has since dropped to #28. It rode the new-phone news cycle, and volume falls once the news passes.

If it were you

Verdict: This is a play that turns system data nobody understands into a shareable identity card. It's not hard to build, and it comes back with every new iPhone launch. But it's free, has no revenue, rides external events, and carries privacy doubts. You can follow it, but you need a clear answer on where the money comes from.

Who it fits: small teams that already run a set of free tool apps and need to funnel traffic to other products; developers who understand iOS diagnostic logs and will update the code tables within days of every new phone; people who know markets like Japan and Taiwan, where specs are a hobby.

Who it doesn't fit: anyone who wants to make money from this one app directly; teams that can't reassure users on privacy, for example if the data has to go to a server; people who don't want to chase new phones every year.

How to do it:

1. Switch markets. FoxPeek has only 3 ratings in the Japan store and 42 in the US. Japanese users also care about screens and batteries. You could ship Japanese first and swap "parts household registry" for wording locals already know.
2. Make privacy the selling point. Korean complaints center on "Chinese app takes serial numbers." Fully offline, works without internet, open-source parsing code: all of this can go in the first screen of the store page.
3. Decide on the paid hook. For example, checking a phone before a secondhand purchase: the seller exports the file, and you get a timestamped inspection report, charged per use or by subscription. Or sell a bulk version to repair shops and secondhand dealers.
4. Build the cards it hasn't built. Battery history, regional model variant, whether parts were replaced: all of these can become equally shareable cards.

How to acquire users: following its playbook, a new phone should get its local language ready a month before launch, and in the first few days of release post a "which screen did my new phone have" screenshot in local iPhone communities (Korea's DC, clien; Japan's 5ch, X; Taiwan's Threads, PTT), so the share card carries the app name and a download link.

When the window was: Sep 2027, before the next-generation iPhone launch. This year's window is closing, and the next one is the launch of next year's phone, so start preparing a month ahead.

What would mean I got it wrong: Apple hides or changes the vendor codes in the diagnostic file in a newer iOS; FoxPeek or SystemBatteryAnalysis builds up Japanese or English markets first; or FoxPeek's daily new Korean ratings drop back to single digits, which would mean this was a one-off meme and not a need that keeps coming back.