What is the 399b app and what makes it different?
Smartphones are now an inseparable part of our lives. Whether you're at home or on the go, the whole world is in your pocket. With that reality in mind, 399b built a dedicated mobile app designed specifically for users in Bangladesh — built to handle slow internet, small screens, and limited data.
What sets the 399b app apart from ordinary gaming apps is its Bangla-first approach. From the interface to notifications, support chat to payments — everything is in Bangla. And it goes beyond just language. 399b understands that people in Bangladesh use bKash and Nagad, that they want to place bets while watching a cricket match at 11 PM, and that they expect a simple, hassle-free experience.
The app is only 28 MB, so it runs smoothly even on older phones. Load time is just 2-3 seconds, even on a 3G connection. Whether you're on a Samsung or a Symphony, the 399b app runs without a hitch.
Everything You Get in the App — Full Feature List
The moment you open the 399b app, it's clear this is more than just a gaming app — it's a complete entertainment experience. Here are the key features:
🎰 Slots Games
500+ slot games available directly in the app. From classic 3-reel slots to 5-reel video slots, free spin bonus rounds, and Megaways slots — every category in one place. 399b's slots section is one of the largest mobile slot collections in Bangladesh.
⚽ Sports Betting
Bet in real time on cricket, football, tennis, kabaddi, and more — all directly from the app. Live scores, updated odds, and in-play betting in one place. The 399b app sees a surge in users especially during IPL, BPL, and World Cup seasons.
🎱 Bingo
The app's bingo section has over 50 rooms — from free-to-play to jackpot rooms. With chat, auto-daub, and multi-card view, playing bingo on mobile has never been easier.
💳 Payment Section
Deposits and withdrawals are handled entirely within the app. bKash, Nagad, Rocket — all major mobile banking options are supported. Send or withdraw funds in just a few taps.
🔔 Smart Notifications
Before a match, on special bonus offers, or during jackpot games — the 399b app sends notifications right when it matters. No unnecessary spam, just useful updates.
How to Download the 399b App — Step by Step
Downloading the app is simple. Just follow the steps below:
Go to Phone Settings
On your Android phone, go to Settings → Security or Privacy and enable "Unknown Sources" or "Install Unknown Apps." This is required to install APK files.
Go to Download Page
From the official 399b website Download Page Go ahead and download the Android APK file. The file size is only 28 MB.
Install the APK
Once the download is complete, open the APK file from your file manager and tap "Install." The installation will finish in just 15-20 seconds.
Create an account or log in
When you open the app, you'll see options to register or log in. New users can create an account in just 2 minutes — all you need is a phone number.
Deposit & Start Playing
Deposit via bKash or Nagad and pick your favourite game. Get a 100% bonus on your first deposit.
For iOS users
The 399b app for iPhone and iPad is coming to the App Store soon. In the meantime, use the 399b mobile website on Safari — the experience is nearly identical to the app.
App vs. Mobile Website: Which is better?
A lot of people ask — is there any downside to playing on the browser instead of downloading the app? Honestly, no, the browser works fine. But the 399b app offers a few extra benefits you won't get on the browser:
| Features | Mobile Browser | 399b App |
|---|---|---|
| Loading Speed | Medium | Fastest |
| Push Notifications | ||
| Offline Cache | ||
| Fingerprint Login | ||
| App-Exclusive Bonuses | ||
| Screen Resolution Optimization | Limited | |
| Data Saver Mode | ||
| Bangla Keyboard Integration | Limited |
* Browser users can access all core games and payment features, but the extra benefits listed above are exclusive to the app.
Exclusive Benefits for App Users
399b is more than just a gaming platform — it genuinely takes care of its app users. Some benefits are only available when you download the app:
- App Welcome Bonus: Log in from the app for the first time and get a 50 BDT bonus credit — no deposit required.
- Daily Check-In Reward: Check in daily to earn rewards that grow over time. Log in 7 days in a row and unlock a special bonus.
- Exclusive Tournaments: Some slots and Sports Betting tournaments are open exclusively to app users.
- Fast-Track Support: Support requests sent through the app typically get faster responses than those from regular browser users.
- Live Match Alert: Get push notifications before your favorite team's match kicks off — so you never miss a moment.
- Data Saver Mode: Automatically reduces data usage on 2G or weak networks to keep games running.
Security & Privacy — How Safe Is the 399b App?
Many people wonder before downloading a mobile app — will this app steal data from my phone? 399b is completely transparent about this.
The app only requests the permissions it actually needs — storage (for APK cache) and notifications (for alerts). It does not ask for camera, contacts, or location access. All data is transmitted over SSL-encrypted connections. Payment information goes directly to bKash or Nagad servers and is never stored on 399b's servers.
The fingerprint login feature uses your phone's own secure enclave, so your biometric data never reaches 399b. That level of security is something even many major international platforms don't offer.