Which apps can I actually connect to Spanbox, and is Signal supported yet?

It's 60+ and growing, and the rule of thumb is simple: if the app has a web version, Spanbox can span it. Confirmed ones include WhatsApp, Slack, Gmail, Telegram, Discord, Microsoft Teams, Instagram, Messenger, Outlook, Proton Mail and ChatGPT, plus a long tail of others. Signal specifically is NOT in yet, and it's honest about why: Signal (along with Viber, LINE and KakaoTalk) has no official web app, so there's nothing for Spanbox to load locally. Those sit on the roadmap until there's a web version to bridge. So check whether your must-have app has a web login, if it does, you're almost certainly covered.

Signal's the common ask and the answer's 'not yet', purely because Signal has no web client to run. Same reason Viber and LINE aren't there. Everything with a proper web app (WhatsApp, Telegram, the Google/Microsoft stuff) works.