Yes, it works without the app.
I don't know if it needs it when you first set it up.
But if you don't want to use the app, I wonder if you could just as easily buy a much smaller, cheaper Roomba model.

Hello Anonymous
Thank you for your question. Firstly to answer your question and as Eboreg has already mentioned, it is very possible to use the Roomba i7 without an app. You can press the three buttons on the robot itself;

CLEAN button to start or stop the robot. When cleaning, it moves in a straight line.
HOME button to send the robot home.
SPOT button to clean an area of 1m2 of your choice. The robot moves in an increasing circle at the spot where you place it.

Roomba i7 is equipped with great app features, such as room-to-room cleaning. You can also create personalised cleaning routes, set up schedules, or use the map to limit the areas you don't want the robot to clean. If you don't want to use the Roomba i7 with the app, we honestly recommend the Roomba i3. The Roomba i3 differs from the Roomba i7 mainly in the app features, but the cleaning performance is the same - for example, the Roomba i3 has the same suction strength, battery life, rubber blades and side brush. If you need more information, please contact us directly.

We would also like to mention that the privacy of our users is very important to us. To this end, iRobot uses only the highest data security standards. The commitment to data security is demonstrated by the fact that the highest standards are also used for data encryption and this has already earned iRobot an official TÜV certification in the area of cybersecurity for the Roomba j-series, for example.

If you have any further questions or uncertainties, please do not hesitate to contact us directly. We can be reached by phone at +41 62 746 06 74 or by email at service@irobotics.ch.

Best regards,
Your iRobot Team