Privacy Policy

1. Who we are

LK Software is an independent software studio operated by Lê Mạnh Kha in Vietnam. We publish desktop applications for Windows. We are the party responsible for this website and for the apps listed below.

Questions about this policy: SUPPORT_EMAIL_PLACEHOLDER

2. Two different things, kept separate

Most privacy policies blur the app and the website together. Ours does not, because the difference is the whole point.

3. The apps

3.1 FastSheet

FastSheet is a read-only viewer for large .xlsx and .csv files. It opens and searches them entirely on your machine.

• Your file is never uploaded. There is no server to upload it to. The app has no cloud storage, no sync, and no import/export to any online service.
• No telemetry, no analytics, no crash reporting. The app does not report what you open, how often you use it, or that you use it at all.
• No account, no password. There is no identity database, so there is none to breach.
• Exactly one network call exists in the app, and only if you choose to make it: when you enter a license key to activate a paid copy, the app contacts api.lemonsqueezy.com once to check that the key is valid. It sends the license key and nothing else — no file, no filename, no file contents. After that, the app stores the result locally and does not re-check on every launch.
• If you never activate a license, the app makes no network calls at all. Airplane mode changes nothing about opening a file.
• This is enforced, not just promised. The app ships with a content security policy that permits connections only to api.lemonsqueezy.com and blocks every other destination outright. You can verify all of the above with any firewall or network monitor — we would rather you check than take our word.

FastSheet stores its settings and, if you activate one, a local record of your license on your own PC. Removing the app removes them (see Uninstall).

3.2 PinRail

PinRail is a free edge-dock launcher. It has no network capability whatsoever — its security policy allows no external connections at all, so there is no license check, no update ping, and no telemetry.

PinRail saves the items you pin and your settings to two files on your own PC, at %APPDATA%\pinrail\ (pins.json and settings.json). These stay on your machine. We never see them.

4. This website

This site is a set of static pages. It has no login, no forms, and no file uploads.

• Hosting. The site is hosted on Cloudflare Pages. Like every web host, Cloudflare processes standard request data (including your IP address) to deliver pages and to protect the site from abuse. We do not use that data to profile visitors.
• Analytics. We use Cloudflare Web Analytics to count page views so we know whether anyone is reading. It is cookieless: it sets no cookies, does not fingerprint your device, does not track you across other sites, and does not collect personal information. There is no advertising network, no Google Analytics, no Meta pixel, and no session recording on this site.
• Cookies. We set none. Nothing on this site needs consent to store data on your device, because nothing stores data on your device.

5. If you buy FastSheet

Purchases are handled by Lemon Squeezy, which acts as our merchant of record. That means Lemon Squeezy — not us — takes the payment, issues the invoice, and handles VAT and sales tax.

• What Lemon Squeezy collects: the details needed to sell you software and charge tax correctly — typically your name, email address, payment details, and country. This is processed under Lemon Squeezy's own privacy policy, and their checkout is where you give it.
• What we see: the order record (name, email, country, what was bought) and the license key issued to you. We use your email to deliver the license and to answer support requests about your order.
• What we never see: your full card number. We do not touch card data at any point.
• What Lemon Squeezy never sees: your files. They see a purchase and, at activation, a license key. Your data never reaches them, because it never leaves your PC.

6. If you email us

If you write to support, we receive your email address, your message, and anything you attach. We keep the thread as long as needed to help you and to keep a record of the purchase.

Please do not send us your spreadsheet. We do not want it and do not need it. If a file misbehaves, tell us its size, its type, and what happened — that is enough for us to work with. If you have already sent one and want it deleted, ask, and we will delete it.

7. Your rights

Depending on where you live, you may have rights to access, correct, export, or delete personal data we hold about you, and to object to its processing.

In practice we hold very little: an order record and a support thread, if you have one. There is no usage profile to hand over, because we never built one. To exercise any right, email us and we will action it. If your request concerns billing data held by Lemon Squeezy, we will point you to them or pass the request along.

8. Children

Our apps are business tools and are not directed at children. We do not knowingly collect personal information from anyone under 16.

9. Changes to this policy

If we change this policy, we will change the date at the top of this page. If a change is significant — for example, if an app ever gained a feature that sends data anywhere — we would say so plainly here rather than bury it. An app that quietly started phoning home would be a different product than the one you bought.

10. Contact

LK Software · Vietnam · SUPPORT_EMAIL_PLACEHOLDER

See also: Terms · Refund Policy · Support