Hi @mihnea-calugaru, thanks for getting in touch. Could you kindly clarify which model of Tobii Eye Tracker you currently have.
It would also be useful if you would elaborate on the intentions for this heatmap application.
The use of eye tracking data from a Tobii Tech Eye Tracker (4C, ET5) for long term storage, analysis or research purposes is expressly forbidden by the user licence agreement which you can read about @ https://developer.tobii.com/license-agreement/
If the intention however if purely interactive (or for gaming) then you may use our SDK such as interaction library or stream engine API freely.
You are correct that we do not currently have a heatmap generator software for users, however many 3rd party applications are available that purport to support Tobii Trackers such as http://www.pygaze.org/
However, the easiest solution would be to find a generic heatmap generator algorithm such as https://github.com/TobiasRoeddiger/GazePointHeatMap and use this in conjunction with the Tobii Interaction Library to ensure that the gaze data is not being stored.
Do let us know if you require any further information. Best Wishes.