Miro (https://miro.com/) is a collaborative whiteboarding system popular with (interaction) designers but also used in research and strategy planning.

Microsoft Teams allows the following events from Miro to be shown:

• invitees sign up
• board is shared with you
• there's a new comment or a reply to your comment on a board
• someone @mentions you in a comment or reply.

Source: https://help.miro.com/hc/en-us/articles/360017572514-Microsoft-Teams

It would be nice to have a similar integration in Mattermost.