Windows — License Tiers
PupilMetrics uses a machine-bound license on Windows. On first launch you are prompted to start a free trial or enter a license key.
| Tier | Duration | Machines |
|——|———-|———-|
| **Trial** | 14 days, full features | 1 |
| **Standard** | 1 year | 1 |
| **Professional** | Lifetime | 1 |
| **Enterprise** | Lifetime | Multiple |
**Starting the free trial**
Click **Start Free Trial** on the license screen. The 14-day countdown begins immediately. All features are available during the trial — no credit card required.
**Entering a license key**
1. Purchase a license key from CNRI.
2. On the license screen, paste your key into the **License Key** field and click **Activate**.
3. Activation contacts `licenses.cnri.edu` to bind the key to your machine ID.
4. Once activated, PupilMetrics works offline indefinitely.
**Trial expired**
If your trial expires, the license screen appears at startup. Enter a purchased license key to restore full access.
> **Note:** Moving a license to a new machine requires contacting CNRI support to unbind the old machine ID.
#### Android & iOS — In-App Purchase
On mobile, licensing is handled through the App Store / Google Play via RevenueCat. Tap **Subscribe** or **Purchase** on the paywall screen to unlock the full app.
