Tasks
You can create tasks related to a Contact or Company and keep a history of both open and completed tasks.
To add a Task to a Contact/Company, open the View screen and tap or click on + then select Task.
The list of added tasks appear in the Activity tab of the Contact/Company View screen on the mobile, and in the Tasks box of the Contact/Company View screen on the web.
N.B.: the tasks attached to Contacts/Companies also appear in the Tasks app.