Right now we do this with the Chrome extension (you can have a panel in Twitter / Messenger without leaving the page). The calendar integration also helps if you use calendar invites, but that isn't relevant to all interactions. Email is on the roadmap.

For other channels like Messenger and Whatsapp, a big constraint is no API for messages. Making an integration for these channels the 'right way' is a challenge we're still working on -- we could ask for user credentials but that doesn't seem like a great long-term solution.