You can turn off the notification to log a meeting from the notifications settings in the Tact app. Here are the steps:
1. Open Tact Sales Assistant app
2. Tap on the "More" tab
3. Tap on "Settings"
4. Tap on "Notification Settings"
5. Turn of Capture Meetings (please see screenshots for more detail)
Your Reminder notifications settings should like the screen shot below:
It's best practice to leave your meeting reminder notifications turned on so you can be reminded to log your activity to Salesforce. It's also good to know that you will only receive Capture Meeting notifications for events that has invitees.