Uninstalling the stratejos slack app is straight forward.
If you can remember your team's subdomain (e.g. https://yourteamname.slack.com) then you can visit https://yourteamname.slack.com/apps/A35G04DNX-stratejos
If you can't remember your team's subdomain or that link format isn't working then try the step by step process below.
Step by Step
Step 1: Open slack in your browser
Go to slack.com and login to your team.
Step 2: Navigate to Apps & Integrations
Then in the top left hand corner of the slack chat window click "Apps & Integrations" as per the image below.
You will now see the slack apps marketplace. Click on 'Manage' in the top right corner.
Find stratejos in your list of integrations and click on it:
Step 5: Click Remove App
You will now see the stratejos app page. Scroll down and click Remove App.