Mobile App

The 399b App — Your Whole Casino in Your Pocket

Download the 399b app and take your gaming wherever you go. One-tap login, instant bKash and Nagad deposits, and full access to every game on the platform — all running smoothly on any Android or iOS device, even on a slower mobile connection.

500+

Games available in the 399b app

<30MB

Lightweight app size — installs in seconds

Android
& iOS

Works on both major mobile platforms

24/7

In-app support available any time

Casino
Fishing
Slots
Jackpot
Play Now

Download the 399b App

Follow these steps to install the 399b app on your device and start playing within minutes.

Android
iOS
  1. 1
    Visit 399b on Your Browser Open your Android browser and go to 399b.net. Make sure you are on the official site before downloading anything.
  2. 2
    Tap the Download App Button Find the app download button on the page and tap it. The APK file will begin downloading to your device.
  3. 3
    Allow Unknown Sources Go to Settings > Security and enable "Install from Unknown Sources" so your phone allows the APK to install.
  4. 4
    Install and Open the App Open the downloaded APK file, tap Install, and wait a few seconds. Once done, open the 399b app and log in or register.
Register to Get the App
App Size Under 30 MB
Android Version 5.0 and above
iOS Version 12.0 and above
Languages English, Bengali
Last Updated 2025

Why the 399b App Is the Best Way to Play

The browser works fine, but the app is a different level. Here is what you get.

Faster load times than the mobile browser — games open in under 3 seconds
Push notifications for new bonuses, promotions, and deposit confirmations
Biometric login — use your fingerprint or face ID to log in instantly
Partial offline mode — browse games and check your balance without a connection
App-level encryption — your session is more secure than a browser tab
One-tap bKash, Nagad, and Rocket deposits directly inside the app

App-exclusive bonus: Players who download the 399b app and make their first deposit through it receive an additional bonus on top of the standard welcome offer. Log in or register to see your current app bonus offer.

No Play Store required: The 399b Android app is installed directly via APK. This means you do not need a Google Play Store account and the app is not subject to Play Store restrictions. The process is safe and takes under two minutes.

Free to download: The 399b app is completely free. There are no subscription fees, no hidden charges, and no in-app purchases required to access any game or feature on the platform.

Everything Inside the 399b App

One app. Every feature you need to play, deposit, withdraw, and win.

Full Game Library

Every game available on the 399b platform is accessible inside the app — casino games, fishing games, slots, jackpots, and more. The app loads games faster than the browser and handles graphics smoothly even on mid-range Android phones common in Bangladesh.

Instant Deposits & Withdrawals

Top up your 399b account using bKash, Nagad, or Rocket directly from the app without switching to a browser. Withdrawals are processed just as fast. The app keeps your payment methods saved so you can deposit in a few taps whenever you want to play.

Bonus & Promo Alerts

Never miss a promotion again. The 399b app sends push notifications directly to your phone when a new bonus is available, when your deposit is confirmed, or when a limited-time offer is about to expire. You stay in the loop without having to check the site manually.

Biometric & One-Tap Login

Set up fingerprint or face ID login on your device and you will never need to type your password again. The 399b app supports biometric authentication on all compatible Android and iOS devices, making login faster and more secure at the same time.

In-App Live Support

The 399b app has a built-in live chat feature so you can reach the support team without leaving the app. Whether you have a question about a game, a deposit issue, or need help with your account, a real support agent is available 24 hours a day, 7 days a week.

Game History & Stats

Track your gameplay directly inside the 399b app. View your full game history, check your win and loss records, monitor your deposit and withdrawal history, and keep an eye on your active bonuses — all from a clean, easy-to-read dashboard inside the app.

App vs Mobile Browser

See why the 399b app gives you a better experience than playing through a browser.

Feature 399b App Mobile Browser
Game Load Speed Under 3 seconds Slower on weak connections
Biometric Login Supported Not available
Push Notifications Yes No
One-Tap bKash Deposit Yes Requires extra steps
Session Security App-level encryption Standard SSL only
Offline Balance Check Available Requires connection
App-Exclusive Bonuses Yes Not available
In-App Live Chat Built-in Opens separate window

Everything You Need to Know About the 399b App

The 399b app is the most convenient way to access Bangladesh's top online gaming platform. Whether you are commuting, relaxing at home, or just have a few minutes to spare, the app puts the full 399b experience right in your hand. It is lightweight, fast, and designed to work well even on older Android devices with limited RAM.

Unlike many gaming apps that strip down features for mobile, the 399b app gives you everything the desktop site offers — and then some. You get the full game library, complete account management, all payment options, and the same bonuses and promotions. The only difference is that everything is faster and easier to use on a touchscreen.

Is the 399b App Safe to Download?

Yes, the 399b app is completely safe. The APK file for Android is hosted on the official 399b website and is scanned regularly for security issues. The app uses the same 256-bit SSL encryption as the website, and all your personal and financial data is protected at all times. Thousands of players in Bangladesh use the 399b app every day without any issues.

When you install the APK on Android, your phone may show a warning about installing from unknown sources. This is a standard Android security prompt that appears for any app installed outside the Play Store — it does not mean the app is unsafe. Simply follow the steps in the installation guide above to allow the installation and proceed.

Which Devices Work with the 399b App?

The 399b app is compatible with a wide range of devices. On Android, you need version 5.0 or higher — which covers the vast majority of smartphones currently in use across Bangladesh. On iOS, you need version 12.0 or higher. The app has been tested on popular budget Android models and runs smoothly without requiring a high-end device.

If your device is running an older version of Android or iOS, you can still access 399b through the mobile browser. The website is fully responsive and works well on all screen sizes. However, for the best experience, we recommend updating your device software if possible and using the app.

Deposits and Withdrawals in the 399b App

The 399b app supports all the same payment methods as the website — bKash, Nagad, Rocket, and other local options popular in Bangladesh. Deposits are processed instantly and your balance updates in real time inside the app. Withdrawals are typically processed within a few hours, and you will receive a push notification when your withdrawal is confirmed.

The app saves your preferred payment method so you do not have to re-enter your details every time. This makes topping up your account a quick, two-tap process — ideal when you want to jump into a game without any delays.

App Bonuses and Promotions

399b offers exclusive bonuses for players who use the app. These include app-only deposit bonuses, cashback offers, and occasional free spins or game credits. To see your current app bonus offers, log in to your account through the app and check the promotions section. New offers are added regularly, so it is worth checking back often.

If you are a new player, registering through the app also qualifies you for the standard 399b welcome bonus on your first deposit. This is the same welcome offer available on the website, but app users may also receive an additional top-up as part of the app launch promotion.

Troubleshooting Common App Issues

  • If the APK fails to install, check that "Install from Unknown Sources" is enabled in your Android settings
  • If the app crashes on launch, try clearing the app cache from your phone's app settings and restarting
  • If games are loading slowly, switch from Wi-Fi to mobile data or vice versa to find a more stable connection
  • If you cannot log in, use the password reset option or contact the 24/7 support team via live chat
  • If push notifications are not arriving, check that notifications are enabled for the 399b app in your phone settings
  • For iOS trust profile issues, go to Settings > General > VPN & Device Management and tap Trust next to the 399b profile
App FAQs

Yes, the 399b app is completely free to download and install. There are no fees, subscriptions, or in-app purchases required to access any feature or game.

No. If you already have a 399b account, just log in with your existing credentials. Your balance, bonuses, and game history all carry over to the app automatically.

Yes. bKash, Nagad, and Rocket are all supported directly inside the 399b app. You can deposit and withdraw without leaving the app at any point.

Google Play has restrictions on real-money gaming apps in certain regions. The 399b app is distributed directly via APK, which is a standard and safe method used by many gaming platforms worldwide.

Ready to Play on the 399b App?

Register for free, download the app, and claim your welcome bonus. The full 399b experience — casino, fishing, jackpots, and more — is waiting for you on your phone right now.

18+ only. Please gamble responsibly.