Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Melrose Labs SMSC Simulator - SMPP SMSC simulator to test SMS messaging applications.
Standard Notes - A safe place for your notes, thoughts, and life's work
Twilio - Brings voice and messaging to your web and mobile applications.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.