Install Checklist for Salesforce.

Install Package in your Organization
from the App Exchange or direct from here

Supported Salesforce Editions: Group, Professional, Enterprise, ...

Install

Checklist

Install the application (v1.9) in your Salesforce organization
https://login.salesforce.com/packaging/installPackage.apexp?p0=04t1I000003cowS&p1=full
or in your Sandbox
https://test.salesforce.com/packaging/installPackage.apexp?p0=04t1I000003cowS&p1=full

Checklist4Sf is a native Salesforce Application designed for Lightning and Classic UI.

We suggest to install the apps for All Users or Specific Profiles.
You can also use Permission Sets for Checklist User and Administrators.