Zulip committed the cardinal sin of stripping out notification support from their mobile apps for anyone not paying to force people to pay them.<p>Every other messaging app out there that is open source covers the minimal costs associated (and for Zulip, with an unpaid userbase that is <i>tiny</i>, these costs are laughably small) to host the infra associated. Note that Firebase Cloud Messaging itself is free. Wire, Signal, Threema, every single XMPP app, Element: none of these force users to build and distribute modded apks just to get notifications.<p>It was a tactic and it sucked and it burned any and all goodwill I had for Zulip.