A professional Android SMS API gateway built for developers and businesses who want a private, flat-rate alternative to cloud SMS services.
Existing cloud SMS services are expensive, complex to set up, and route your messages through third-party servers. We built a better way.
A local-first, 4-step architecture that keeps your messages private while delivering enterprise-grade reliability.
Your application sends an HTTP POST to the cloud endpoint with your API key, phone number, and message text.
Firebase Cloud Function validates your API key and forwards a push notification (FCM) to your registered Android device.
SMS Gateway Master on your Android phone receives the FCM and uses the native SmsManager to deliver the SMS through your carrier.
Delivery status (sent / delivered / failed) is POSTed back to your webhook URL in real-time for tracking and retry logic.
Everything you need to send SMS programmatically, manage conversations, and integrate with your systems.
Simple HTTP POST endpoint. Works with any language: Python, Node.js, PHP, cURL, Excel VBA, Google Sheets, Bash. No SDK required — just an HTTP client.
Message content is never stored in the cloud. SMS are sent directly via Android's SmsManager. All conversation history lives only on your device in Room Database.
Instant delivery status callbacks for every SMS. Set a default webhook once, or override per-request. Know immediately when messages are sent, delivered, or fail.
Not just an API bridge — it's a complete default SMS app with Material Design 3, dark mode, conversation threads, search, and smart message management.
PRO plan supports up to 10,000 SMS per day via API. Background processing with WorkManager ensures reliable delivery even under high load.
Download production-ready scripts for Python, Node.js, PHP, Excel VBA, Google Sheets, and Bash. Add your API key and start sending in minutes.
SMS Gateway Master is used by developers and businesses for a wide range of SMS automation scenarios.
Send one-time passwords and two-factor authentication codes to users. Instant delivery confirmation via webhook to verify that codes were received.
Automated alerts for order confirmations, appointment reminders, shipping updates, and any event-driven notification from your application or server.
Get SMS notifications when your server goes down, database hits capacity, or any monitored metric exceeds a threshold. Integrate with cron jobs or monitoring tools.
Send promotional SMS to customer lists from Python or Google Sheets. Bulk-send support with per-message delivery tracking through webhooks.
Trigger SMS from your CRM or ERP when a deal closes, invoice is issued, or customer interaction occurs. Works with any system that can make HTTP calls.
When incoming SMS webhooks are released, build two-way SMS automation: reply bots, interactive surveys, customer support flows, and keyword-triggered responses.
A direct comparison with the most popular commercial SMS API providers.
| Feature | SMS Gateway Master | Twilio | AWS SNS | Vonage (Nexmo) |
|---|---|---|---|---|
| Monthly cost | €5/month · €52/yr | $0.0075+/SMS | $0.00645+/SMS | $0.0065+/SMS |
| 10,000 SMS cost | €5 flat/month (€52/year) | ~$75 | ~$64.50 | ~$65 |
| Data privacy | Local — your device | Cloud — their servers | Cloud — their servers | Cloud — their servers |
| Setup time | ~5 minutes | Hours (compliance) | Hours (AWS setup) | Hours (verification) |
| Phone number | Your own SIM | Virtual (extra cost) | Virtual (extra cost) | Virtual (extra cost) |
| Daily limit | 10,000 SMS/day | Unlimited (pay per) | Unlimited (pay per) | Unlimited (pay per) |
| Delivery webhooks | ✓ Real-time | ✓ Available | ✓ Available | ✓ Available |
| Free trial | 7 days, 100 SMS/day | $15 credit | AWS Free Tier limits | Limited sandbox |
Built with modern Android and cloud technology for reliability, performance, and security.
Simpapp is a mobile software development company specialising in professional Android applications. We build tools that solve real developer and business problems — with a focus on simplicity, privacy, and reliability.
SMS Gateway Master is our flagship product: a REST API SMS gateway that puts you in full control of your messaging infrastructure, using hardware you already own, at a fraction of the cost of cloud SMS services.
We believe that powerful developer tools should be affordable, private, and work out of the box in minutes — not hours.
Download SMS Gateway Master from Google Play and send your first API SMS in under 5 minutes. 7-day free trial included.
Download on Google Play View API Documentation