An Embrio license is a one time purchase that does not expire. You can activate your license on up to 3 of your own computers.
Your license is attached to a user account, please create an account to purchase Embrio.
Without a license you can work in connected mode as much as you want, you only need license to compile a program when your project is done and you want to run the Arduino disconnected from your computer.
If you decide Embrio is useful and saves you time and effort, please consider purchasing a license to support its development.