Support for KV Apps
One support address for Khanh Vu's apps. Include the app name so we can check the right product. Features and data handling can differ between apps.
Contact support
Email us with questions, bugs, purchase issues or privacy requests. Response times depend on the request and the number of messages we receive.
khanhvu.dev@gmail.comHow to get help
Email us in English or Vietnamese. Include the app name, version, device, iOS version and steps to reproduce the issue. Do not send passwords, PINs or private content. For eligible purchases, try Restore Purchases in the same app with the Apple Account used to buy. Manage subscriptions with Apple; deleting an app does not cancel a subscription. Request Apple-billed refunds here.
Veilnest — private vault support
Keep private photos and videos in an encrypted space with your own PIN. View Veilnest on the App Store or contact Veilnest support.
How do I unlock my vault?
Use the six-digit PIN you chose for Veilnest. You can also enable Face ID or Touch ID on a supported device. Your vault PIN is separate from your Apple Account password. Never send us your PIN or recovery secrets.
Does importing remove the original photo?
No. Import creates a copy inside Veilnest. Originals remain in Photos or Files until you remove them there. If you choose to delete originals from Apple Photos, also review Recently Deleted. Check your vault copy and keep a separate copy of important content before deleting anything.
How does the calculator cover work?
Enable Panic Protection in Settings, choose Calculator and enable a supported face-down or shake gesture. Triggering that gesture while the vault is open locks it and displays a working calculator. Exit the cover and authenticate to reopen your vault. Calculator digits perform arithmetic; entering a PIN into the calculator does not unlock the vault. Face-down requires a supported device.
Can you recover my PIN or vault content?
Vault content is local to your iPhone and there is no automatic cloud sync or developer-operated vault recovery service. Losing your device, deleting the app or losing access can make content permanently inaccessible. Keep a separate copy of important files and use the export or backup options supported by your installed version. Do not delete the app to troubleshoot an unlock problem.
Which features require Pro?
The free version has a storage allowance. Pro adds capacity and features such as a separate decoy vault, private albums, more notes, Break-in Alerts and advanced camera or editing tools. Check the in-app offer for the current limits, benefits, prices and trial eligibility. For an existing purchase, use Restore Purchases with the Apple Account that made it.
How to hide photos on iPhone · Veilnest privacy information · Terms of Use
Paper Lagoon — game support
Paper Lagoon is in development. Gameplay and progress work offline; ads, purchases and analytics can use online services. Updated October 18, 2026. Explore the game.
Contact Paper Lagoon supportHow do I change the language?
Choose your preferred language in the game's language selector. Your choice is saved on this device without changing your board, progress, attempts or light drops. The native app supports 19 languages. This website is presented in English.
Which way do boats go? Why do the other boats drift?
Tap a boat with a clear, straight path along its pointed end to send it out of the lagoon. The remaining boats then drift one square with the current if nothing blocks them. The four arrows above show the upcoming currents. Boat points and current arrows have different roles.
How much is a hint? What if I'm stuck?
Hints are free in the first five levels. From level 6, a hint costs 8 drops or 1 ticket; every 15 first clears earn 1 ticket. Hints you've unlocked for a board state are free to view again. If the solver proves a dead end, a popup offers recovery or restart with the cost clearly shown. The game doesn't charge for a hint until it finds a winning move. A search timeout doesn't mean there's no solution.
How do light drops and daily mail work?
Your first clear of a level earns 10 drops. Replaying a completed level doesn't grant that reward again. Spend drops on hints, paid undos and dock decorations. Daily mail unlocks after your first clear: 4, 5, 6, 8, 10, 12 and 16 drops over seven consecutive days. Day 7 onward stays at 16; missing a day restarts your streak. Collect the base reward once each day.
What if I run out of attempts? Are undos and restarts free?
You have up to 5 refilling attempts, with 1 returning every 20 minutes. Winning keeps your attempt. Restarting or switching levels after a move asks you to confirm using 1 attempt. In regular levels, the first 2 undos per attempt are free, then cost 2 drops per move. Dead-end recovery costs at most 6 drops. Tutorial levels 1–5 and practice on completed levels are free as explained in the game.
Why don't I see an ad or purchase option?
Paper Lagoon includes advertising and Apple purchase integrations. Availability depends on the installed build, connection, consent choices and service availability; development builds can show test ads. Optional rewarded ads explain the reward before you choose to watch. Any paid product shows its price and benefits in the game and Apple's purchase flow. Offline puzzles remain separate from these online services. See the privacy notice for ads and usage analytics.
Lost progress, quiet sound or a puzzle bug?
Don't delete the app to troubleshoot: saves are local, with no cloud sync or recovery service from us. Check device volume, the silent switch and the music, effects and dock-sound toggles in Pause. If the problem continues, email the level, game and iOS versions, device and reproduction steps. If a screenshot helps, remove private information first.
Paper Lagoon at a glance
Email khanhvu.dev@gmail.com with the level number, game version, device/iOS version and reproduction steps. Progress is local; uninstalling may lose it. There is no cloud sync or remote save recovery. Ad and purchase availability depends on the build and online services. Ads, analytics and purchase records are described in the privacy notice; see the game terms for virtual items and saved progress.
Questions about our apps
1. Where is data stored? Is it encrypted?
Storage depends on the app and feature. On-device features use local data; if an app offers online services or sync, read its specific notice. Not every app has a vault, PIN or file encryption. See our Privacy Policy for details.
2. How do I delete data or move to a new device?
Use the deletion, export or backup features the app actually supports. Deleting an app usually removes its private app storage, but exported photos, backups, synced copies or Keychain items may remain. Offload App differs from Delete App. Check backups or exports before deleting; don't assume Quick Start or iCloud will restore every item.
3. I bought Pro, but it hasn't unlocked.
Check you're using the right app and Apple Account, connect to the internet and choose Restore Purchases where available. A purchase in one app doesn't automatically apply to another. Subscriptions must be active; consumable items usually aren't restored like lifetime access. If the problem continues, send the app name, product and error message, but never your Apple Account password.
4. How do I cancel a subscription or request a refund?
Open Apple subscription settings to cancel before the next renewal. Deleting an app doesn't cancel a subscription. Send Apple-billed refund requests to reportaproblem.apple.com; approval depends on Apple's rules and your applicable legal rights.
5. Can I use an app for commercial work?
Yes. Use our tools for personal or commercial work under the applicable license, plan benefits and rights to your source content. You keep the rights to your own work. This doesn't allow reselling the app or using third-party assets without permission. See our Terms of Use.
6. How do I change camera, photo or advertising permissions?
Open your iPhone or iPad Settings to review app permissions and Privacy & Security → Tracking. If the app provides Privacy Options, use it to review regional advertising choices. Denying tracking doesn't stop all ad-related data processing. Don't include advertising identifiers in support messages.
7. What if I can't unlock an app with PIN or Face ID?
Check that app's recovery instructions. Not every KV Apps app has a lock or the same recovery method. Don't delete the app to troubleshoot without a copy of data you need. We never ask you to email a PIN, password or recovery key.
Color Meter — creative tools support
Sample colors from camera views or photos, explore the color wheel and save colors in local collections. For availability, features or purchase questions, contact Color Meter support. Read the Color Meter privacy information.
8. Color Meter: the camera or photo won't sample colors.
Check Camera/Photos permissions in Settings and try another image. Test the camera on a real device. Results depend on lighting and image processing; CMYK is an approximate conversion. Collections are local. Color Meter has no vault/PIN or KV Apps cloud-sync service.
9. Color Meter: Color Wheel or purchase problems.
Check the latest available App Store version and reopen the app. If the issue continues, send your device, iOS and Color Meter versions, and reproduction steps. You don't need to delete the app, which may erase local collections. For Pro issues, try Restore Purchases on the upgrade screen.
10. How do I report a bug or make a personal-data request?
Send the app name, version, device/iOS, reproduction steps and a screenshot with private information removed if needed. For access or deletion requests about information we hold, state your request in the email. We can't read or delete data held only on your device remotely.