Installing the iOS app
The Ultrathink iOS app lets you capture content on the go from your iPhone. You can save web pages, notes, photos, and voice recordings directly into your knowledge base using the share sheet or the built-in capture tools.
This guide covers how to install the app, connect your account, and verify everything is working.
What you will need
Before you begin, make sure you have the following:
- An iPhone running iOS 16 or later
- An Ultrathink account with a verified email address
- A device key generated from the Ultrathink web app
- An internet connection for the initial setup
Installing via TestFlight
During the beta period, the Ultrathink iOS app is distributed through Apple's TestFlight platform. TestFlight is Apple's official tool for testing apps before they are released on the App Store.
Requesting access
- Visit the Ultrathink website or contact the team to request a TestFlight invitation
- You will receive an email from Apple with a link to join the beta
- If you do not already have TestFlight installed, the link will prompt you to download it from the App Store
Installing the app
- Open the TestFlight invitation email on your iPhone
- Tap View in TestFlight
- The TestFlight app opens and shows the Ultrathink listing
- Tap Install
- Ultrathink appears on your home screen like any other app
Staying up to date
TestFlight handles updates automatically. When a new build is available:
- You receive a notification from TestFlight
- Open TestFlight and tap Update next to Ultrathink
- You can also enable automatic updates in TestFlight settings so new builds install without manual action
Tip: TestFlight builds expire after 90 days. If your build expires, open TestFlight and install the latest version.
Future App Store availability
The Ultrathink iOS app will be available on the App Store after the public release. When that happens, you will be able to download it directly from the App Store without needing a TestFlight invitation. Existing TestFlight users will be notified about how to transition to the App Store version.
Connecting your account
The iOS app uses a device key for authentication rather than a username and password. Device keys are long-lived tokens that keep you signed in without needing to re-enter credentials.
Generating a device key
- Open the Ultrathink web app at app.ultrathink.io
- Go to Settings from the left-hand menu
- Select the Device Keys tab
- Click Create new key
- Give the key a recognisable name (for example, "iPhone" or "iPad")
- Copy the generated key
Tip: Use a descriptive name for each device key so you can identify which device it belongs to if you ever need to revoke it.
Entering the key in the app
- Open the Ultrathink app on your iPhone
- Tap the gear icon to open Settings
- Paste or type your device key into the Device Key field
- Tap Save
The app validates your key and connects to your Ultrathink account. If the key is accepted, you will see your recent entries appear on the main screen.
How your key is stored
Your device key is stored securely in the iOS Keychain. The Keychain is Apple's built-in credential manager, which encrypts data at rest and protects it with your device passcode or biometric authentication (Face ID or Touch ID). This means:
| Security feature | Detail |
|---|---|
| Encryption | AES-256 encryption via iOS Keychain |
| Access protection | Locked behind device passcode, Face ID, or Touch ID |
| App isolation | Only the Ultrathink app can read the stored key |
| Backup behaviour | Keychain data is included in encrypted device backups only |
Verifying the installation
After entering your device key, confirm everything is working:
- Open the Ultrathink app
- The main screen should display your recent entries
- Tap the + button to create a quick test entry
- Enter a title and tap Save
- Open the Ultrathink web app and check that the entry appears
If the entry appears in the web app within a few seconds, your installation is complete and syncing is working correctly.
Troubleshooting
"Invalid device key" error
- Open the Ultrathink web app and go to Settings > Device Keys
- Confirm the key has not been revoked
- Copy the key again and paste it into the iOS app
- Make sure there are no leading or trailing spaces when pasting
App does not install from TestFlight
- Check that your iPhone is running iOS 16 or later
- Make sure you have enough free storage on your device
- Try closing and reopening the TestFlight app
- If the invitation link has expired, request a new one
App crashes on launch
- Update to the latest TestFlight build
- Free up device storage if your iPhone is running low
- Delete and reinstall the app from TestFlight
- Report the crash via TestFlight by shaking your device to send feedback
Next steps
With the app installed and connected, you are ready to start capturing content:
- Set up the share sheet to save content from Safari, Notes, and other apps
- Try voice capture to record and transcribe audio notes
- Learn about syncing to understand how entries stay up to date across devices