On the free plan, you will get 240 minutes of noise-free audio streams per week. The number of minutes will be reset each Monday in the GMT timezone. You can see the number of minutes left and the renewal date in your Krisp app.
The minutes are calculated based on the presence of the audio stream in Krisp app and if the Remove Noise toggle is turned on for either microphone or speaker.
The Remove Noise toggles keep the last preferred state and do not turn off themselves. This means that if Krisp mic/speaker start being used anywhere, the minutes will be counted. An unintentional use, in this case, can be opening the audio settings of an app where Krisp devices are selected even if there is no ongoing call. The devices are being considered as used at that moment.
The minutes renew each week at 12:00 AM GMT. If you've used all your allowance, you would need to wait till the renewal time to get more minutes or upgrade to the Pro plan to get unlimited minutes.
You can only be logged in to Krisp on one device at a time. This means that if you log in to the same account on a second device, you will be logged out from the Krisp app on the first device.