Prospero - Professional Business Proposals
Keybase Chat - End-to-end encrypted chat built into Keybase
Proposify - A simpler way to deliver winning proposals to clients.
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Colibro Proposals - Compose, send, and sign proposals online for free
Seald - Keep your conversations secure, everywhere.