LeadSimple allows you to see your tasks from your calendar more easily on your mobile phone since you don't have to log in to LeadSimple from your browser app.
If you wish to have this connection removed, you can find below the settings that you can look for.
Google Calendar
On your computer, open Google Calendar.
In the top right, click Settings.
In the left column, select the calendar you want to remove.
Click Remove calendar.
Click Unsubscribe.
Click Remove calendar.
Outlook
Login to Outlook.com.
Click on Menu on the left top of the window.
Select Calendar and click on the Settings (Gear icon) at the right top.
Select Calendar you want to delete
Click "Delete" in the top menu.
iPhone
1. Go to the Settings app on your iPhone.
2. Find and tap Accounts & Passwords.
3. Select Subscribed Calendars under the Accounts section.
4. Select the calendar you want to remove.
5. Select Delete Account.
6. Confirm your choice by tapping Delete again.