Some top alternatives to Signal Messenger includes Output Messenger, Trillian, Dialog, Confide and Messenger Communication Platform.
No, Signal Messenger doesn't provide API.
Yes, Signal Messenger provides a mobile app.
Signal Messenger is located in San Francisco, California
Signal Messenger offers Freemium, Open-source pricing models
The starting price is not disclosed by Signal Messenger. You can visit Signal Messenger pricing page to get the latest pricing.