That sometimes happens for various reasons.

1. It could be if you are in a country without access to paid apps.
2. Other reasons include if you purchased a newer model phone, if you recently switched phones, did a firmware upgrade or a factory reset.
3. Or if you are using a phone with Android 1.5 operating system the full version is not available on the Market.  You can still buy it from us directly however.

You can buy the app directly and download from BabyESP.com if you can pay with Paypal. Email Support to start the process.