To uninstall the Please Share app from Slack, follow these steps:
From the Slack desktop client, choose the drop-down menu icon next to your company’s workspace name (top left).
Hover of Settings & administration and select Manage Apps under Administration. This will take you to a Slack webpage.
Choose Please Share from the list of available options.
On the next page, select the Configuration tab (next to Description)
Then scroll down and select the Remove App button
When the popup message appears, select the Remove App button again
To install Please Share, visit this page.