1. Welcome
GSTNet Secure is a private messaging and calling app. Instead of a phone number, you use a GST-ID, an 8-digit number that identifies you. Give your GST-ID to the people you want to talk to.
Your messages, calls and files are encrypted on your device before they are sent. Global Space Technology cannot read them.
This guide describes the iPhone and iPad app. Where the Windows app works differently, the guide says so. Button and menu names are given in English, as they appear in the app's English version.
2. What You Need
- An iPhone or iPad with iOS 26.5 or later: get GSTNet Secure from the App Store.
- Or a Windows 10 or 11 PC: download the app from our Download page.
- An email address and an internet connection (Wi-Fi or mobile data).
3. Create Your Account
iPhone and iPad: open the app and tap New to GSTNet? Create a free account. Enter your email address, create a password and enter it again, then confirm. The app shows Registration Successful and Your GST-ID. Write your GST-ID down.
Windows: register on our Registration page, then sign in to the Windows app.
No phone number or real name is needed. Keep your email account and password safe: for your protection, we cannot bypass account security to recover a lost account.
4. Your Access
| Period | What you can do |
|---|---|
| First 90 days (free) | Every feature. One introductory period per device. |
| Free Access (after 90 days, no cost) | Send and receive messages; answer voice and video calls. |
| Full Access ($79.99 per year) | Everything, including starting voice, video and group calls and sending files. |
Your current plan is shown in Settings → Plan. Nothing is charged when the 90 days end. Full Access is bought on our website with your GST-ID (Pricing page), not inside the app, and it works on every device where you sign in.
5. Signing In
Sign in with your registered email and password. Use the same details on every device; your GST-ID, contacts and conversations follow you.
Forgot your GST-ID? On the sign-in screen, entering your registered email shows the GST-ID assigned to it.
6. Contacts
Open the Contacts tab and tap Add Contact. Enter the person's GST-ID and, if you like, a nickname. Your contact list is saved to your account. GSTNet never reads your phone's address book.
7. Messages
Open the Chat tab, tap New Chat, enter the recipient's GST-ID and start typing.
- Every conversation appears in your chat list, newest first, with a badge for unread messages.
- Messages from people who are not in your contacts are marked Not in your contacts.
- Sent messages show when they are delivered and read.
8. Translating Messages
iPhone and iPad: go to Settings → Language & Translation.
- Message Translation Language: the language you want to read in. Only languages that Apple can translate on your device are listed (about 20).
- Automatic Message Translation: turns translation of incoming messages on or off.
- App Language: the language of the app itself (English, Persian or Japanese).
Translation happens on your device after a message is decrypted. Nothing is sent to us. The first time you use a language, your device may download Apple's language files.
Windows: the Windows app does not translate messages. Message text never leaves your computer.
9. Voice, Video and Group Calls
- Start a call from the Calls tab or from a contact, and choose voice or video.
- Incoming calls ring like normal phone calls, even when your iPhone is locked. Answer or decline on the call screen.
- Group calls: during a call, add more people with Add Person.
- Calls connect directly between devices when possible, and through an encrypted relay when not.
- In Settings you can adjust video quality and reduce mobile data use.
10. Files and Photos
Send photos and files from inside a conversation. They are encrypted on your device, and only the recipient can decrypt them. Large files are sent in pieces and can take a while on slow connections.
To free space on your device, use Settings → Storage & Data → Clear Downloaded Files. This does not delete messages or anyone else's copy.
11. Useful Settings
- Appearance: Settings → Chats → Appearance (System, Light or Dark).
- Notifications & Sounds: alerts for messages and calls.
- Privacy & Safety → Blocked Users: manage people you have blocked.
- Edit Profile: your display name and avatar.
12. Privacy and Security
- Messages, calls and files are end-to-end encrypted. We do not have the keys to read them.
- Our servers store your account details and, in encrypted form only, your messages and files so they can be delivered. Notifications never contain message text.
- Protect your phone with a passcode. Anyone who can unlock your phone can read your conversations.
Full details are in our Privacy Policy.
13. Deleting Your Account
Go to Settings → Account → Delete Account and confirm. This is permanent: your account, GST-ID, access and device links are removed, and they cannot be recovered.
If you have Full Access, cancel the renewal first by emailing support. Deleting the account does not cancel a payment.
14. Help
- Not receiving calls or messages? Allow notifications for GSTNet in your iPhone's Settings (Settings → Notifications & Sounds → Open iOS Notification Settings).
- A feature asks for Full Access? After the first 90 days, starting calls, group calls and sending files need Full Access.
- Lost your password? Contact support from your registered email address.
Support: Support page · support@globalspacetechnology.com. Include your GST-ID, and never send us your password.