The PDF reader that ranked behind LinkedIn and Blind: how a Pakistani developer squeezed into #3 on the Korean Business Top Grossing chart

PDF Reader - Scan & Edit PDF is a very ordinary PDF reader on Google Play, with a developer based in Pakistan. In Nov 6 it entered the Korean Business Top Grossing chart at #3 and Japan at #6. It looks like a new release that hit 500k installs in two weeks, but it's actually an old package listed about 7 months ago that gains only two or three thousand installs a day. It charted not because of the product, but because of two moves anyone can make: putting it in the Business category, and writing "HWP" in the Korean-store title. Below, I explain why those two moves work, where the money comes from, and why it isn't worth copying to build yet another one.

No. 3 on the Korean Business Top Grossing chart

In Nov 2026 6, the Korean Google Play Business category Top Grossing chart: #1 LinkedIn, #2 Blind (the anonymous workplace community, 5.18M installs), #4 Jobplanet (the recruitment review platform). Sandwiched in between at #3 is "PDF 리더: HWP, DOCX, PPT 뷰어," a PDF reader.

The "About the developer" section at the bottom of the store page lists Muhammad Attiq ur Rehman, with an address that is a PO box in Bahawalpur, Punjab, Pakistan. The support email is [email protected], the website is an app-ads-txt hosting subdomain, and the privacy policy is hosted on Google Sites. The developer is called Lime Spark Apps and has 4 apps in total: this PDF reader, two device-transfer tools, and a football scores app, with over 700k installs combined (AppstoreSpy developer page). The PDF reader accounts for over 50 million of those.

On the same day it was #6 on the Japanese Business Top Grossing chart and #18 in India. In another dozen or so countries (Vietnam, Indonesia, the Philippines, Mexico, Poland...) it sits between #18 and #21, and the ranks move together each day. This is the Google Play small-country charts sharing one aggregated ranking, and doesn't mean there is real revenue in those countries. Only Korea and Japan matter.

What it is

A tool that opens every document type: PDF, Word, Excel, PPT, TXT, with HWP / HWPX added for the Korean store (the Korean document formats used by government, schools, and companies). Other features include camera scanning, OCR text extraction, PDF signing and annotation, merge/split/compress, and encrypt/decrypt. Free to download, with ads, and in-app purchases from $19.99 to $69.99 per tier (US Google Play store, 11-06).

The feature list is word-for-word the same as hundreds of similar apps in this category. The store description is a standard template, and the English version even repeats its opening paragraph twice.

"Two weeks, 500k installs" is a misreading

The first-release date on the store is Oct 2026 24. If you only look at that, 6 516k installs in Nov would mean 500k installs ramped up in two weeks, which looks very impressive.

But AppstoreSpy shows the app was listed about 7 months ago, and the developer's first app went up in Aug 2025 1. Oct 24 also happens to be the date of one of its updates, so the "first release" date on the store was probably reset at that point (inferred, cause unverified: it may have been relisted, or the store page may have been heavily revised). When I first saw it in Oct 29 it already had 497k installs, which is consistent with it having built up slowly.

Actual growth looks like this:

Over the past 7 days +18,564, about 2,600 times a day. All Document Reader, built on the same template, gained 180k in the same week, and Lumio Tech's "PDF Reader: View All PDFs", launched in November 2025, gained 970k. It's a small player in this category.

Why it charted: one category choice, one title change

Put it in Business. Most similar PDF readers cluster in "Productivity" and "Tools": among Google Play apps with PDF in the title, 266 are in Productivity and 165 in Tools, and only 86 are in Business. The competitors on the Korean Business Top Grossing chart are LinkedIn, Blind, recruiting, and enterprise software, most of which don't make money from in-app purchases, so the chart bar is very low. A tool with a few hundred thousand installs can get into the top 3 with a few subscriptions a day (inferred, no revenue data). The ranking itself is also exposure: besides the category chart, the store page shows a ranking badge, and in Nov 6 its Korean store page displayed "#3 최고 매출 비즈니스" (Top Grossing Business #3).

One title per country. The Korean store title is "PDF 리더: HWP, DOCX, PPT 뷰어," the Japanese is "PDFリーダー:スキャン・OCR・編集," the Hong Kong one is "PDF閱讀器 - 掃描與編輯," and there are also titles in Spanish, Dutch, Turkish, Vietnamese, Thai, Arabic, and Malay. The Korean description was rewritten in full, opening with "Document files commonly used in Korea... HWP/HWPX, PDF, Word," and specifically mentioning "students who view HWP courseware and office workers who review HWPX files."

However, the search traffic from the title change may not be as large as it seems. Searching "hwp 뷰어" or "한글 뷰어" in the Korean store, it doesn't appear in the top 30 results: the leaders are Hancom Office Viewer (10M+), Hancom Docs, Polaris Office, and several HWP readers whose titles literally say "광고 없는" (ad-free). It ranks 28 for "pdf 리더"; searching "PDFリーダー" in the Japanese store it's also 28 (11-06 checked with Korean and Japanese store settings, so results may differ from a real device). So where its volume comes from isn't fully clear: search gives some, chart exposure gives some, and the rest is probably paid acquisition (inferred, I haven't seen its ad creatives). The app-ads-txt hosting site on the store page is a common setup for ad monetization and doesn't by itself prove it is running ads.

Where the money comes from, and what users say

Two legs: ads, plus a $19.99 to $69.99 paywall. Korea and Japan are willing to pay for tools, which is why it ranks much higher on the Korean and Japanese Top Grossing charts than in other countries.

Few reviews, but they tell the story. The Korean store has 31 ratings averaging 4.2 stars: 24 at 5 stars and 6 at 1 stars, with nothing in between (Google Play, Korean store, 11-06). Among the reviews with text, the few 5-star reviews from the US store are dated between Oct 29 and Nov 2, and say things like "Good", "Fast Processing", "This is amazing application". There is also one 5-star review that reads "co fused" (confused). The only thoughtful one is from a Japanese user in Oct 28, a 1-star review: "The ads are seriously annoying!! Even after updating, I have to do the same operations over and over again, and I'm fed up" (translated from Japanese).

Who it's competing with

• Big companies and official products: Adobe Acrobat Reader (940M installs), WPS Office (830M), Microsoft Word (2.69B), CamScanner (580M). In the Korean HWP segment there is Hancom's official Hancom Office Viewer (20.5M) and the homegrown Polaris Office (76.5M).
• Same-template players at scale: PDF Reader - Easy PDF (430M installs, +7M over the last 1.85 days); All Document Reader (13.1M, +7k over the last 180 days). It's also in the Business category and charts alongside it, #7 on the Korean Business Top Grossing chart and #9 in Japan, at 25 times its scale.
• Korean HWP readers: there are over 30 document readers with HWP or 한글 in the title, with a dozen or so template developers rushing in between 2025 and 2026. One has already reached 500k installs by making "ad-free" its selling point.

On every one of these lines it isn't the first, and it isn't the biggest.

If it were you

One-line verdict: the package itself isn't worth following. What's worth remembering is the two zero-cost moves: pick a niche category, and change titles by country.

Who it suits: developers who already have a working utility app and want to squeeze out a bit more exposure and payments. Treat it as two checks on your listing checklist.

Who it doesn't suit: anyone who wants to build a PDF reader from scratch. This category has hundreds of similar apps, a handful of giants, and a crowd of factories scaling with paid acquisition. What you ship would be number 548; the HWP niche already has official products and over 30 template packages.

How to do it: Check which category has the lowest bar to a top-chart spot. Business, education, and health are often held by big companies that don't rely on in-app purchases, and you can place your tool there as long as it complies with Google Play's category rules. Then write the country-specific search terms into the title and description, such as HWP for Korea or OCR for Japan. If you do build a document reader, go after what the others get wrong: Korean users are searching for 「광고 없는 HWP 뷰어」 (HWP viewer without ads), and a clean, one-time-purchase HWP reader has a better shot than yet another PDF reader full of ads.

How to get users: This category has no content channel. Nobody on X or TikTok is talking about it, and no media outlet has written about it. What works is store search, category chart exposure, and paid acquisition.

When was the window: There was no window. Both the category and title tactics have always worked, and people have always been using them.

What would show we're wrong: (1) If its daily installs climb to over 10k a day before year-end, or Lime Spark Apps keeps shipping new apps with the same playbook, it means they're earning more in Korea and Japan than the chart position suggests, and the path is wider than we estimated. (2) If its Korean chart rank drops out of the top 20 in Business Top Grossing, it means the top 3 was propped up by a short burst of paid acquisition or a few big purchases, and the category tactic was overrated. (3) If the HWP readers marketing "no ads" keep rising in rank and installs, it means the real opportunity in this niche is the product, not distribution.