The best alternatives to fugacious are Lexicon, Stealthy, and Whodini. If these 3 options don't work for you, we've listed a few more alternatives below.
Lexicon is a customizable, open-source mobile app that provides an elegant mobile discussions experience. Built on Discourse, an open-source platform for communities. Fork Lexicon, connect it to your existing Discorse instance, and ship it to the App store!
Stealthy messages are encrypted before leaving your phone for true end-to-end encryption. It is decentralized, meaning your data is not stored on any servers and your messages go directly to your friends--no middleman. Stealthy even features public channels for chatting with new people and the worlds first decentralized Ask Me Anything!
Fossa is modern open source management. Realtime license and vulnerability management for open source dependencies. Integrate realtime license audits, vulnerability scans and reporting at the speed of development and delivery
the blik redefines secure messaging by enabling you to chat and control the chat with only a the blik id. Нo email addresses, no sharing of personal data! Just a messenger with a non-shareable contact address – only 1 person who has the blik id can contact you