Max SMS is a free Mac app for sending and receiving SMS messages through the Twilio Programmable SMS service.

macOS — Max SMS.app v2 (595 KB)
iOS Sign up for the public beta test on TestFlight https://testflight.apple.com/join/Md2b23I3

This app is great for business who want to send and receive SMS messages on a shared Twilio phone number.
sms-list
Twilio lets you (in countries that permit it) send SMS messages from alphanumeric senders. This gives instant identification to your customers it is your company sending the message. Max SMS lets you send these messages straight from your Mac as long as you have internet access.
sms-send
When adding an account you can either use the Twilio accounts credentials or you can use an API key. You also have the choice of requiring system authentication to access the auth token.
sms-account
Note: Some providers DO NOT allow Twilio phone numbers to be used for SMS Two-Factor authentication, they detect this and give you no indication that's why it doesn't work. Check with your service provider they allow Twilio phone numbers before paying for one.

SMS Two-Factor Authentication is unfortunately very insecure for a number of reasons:

  1. It is very easy to steal someone's phone number.
  2. SIM cards are usually not PIN locked and are easily removed from phones.
  3. Recovering a taken over account usually takes a long time, especially when attackers choose times of day when telco support is closed.

In addition to that, if you work in a team environment you may need to:

  1. Give coworkers or contractors access to accounts.
  2. Management may require unrestricted access to accounts.
  3. Transfer access to accounts when leaving the company.

If these accounts have SMS Two-Factor authentication then using a personal phone number is inappropriate. A company phone number is the only option, but having access to the SMS messages a physical phone receives is impossible for many teams.

Twilio is an online service that allows you (for a cost) to create "electronic phone numbers" that can receive SMS messages. These phone numbers do not have physical SIM cards that can be lost. They can be accessed by anyone with an API key so access can be shared inside a team or with contractors. API keys can be revoked when an employee leaves the company.

Max SMS is a Mac app that makes it easy to view these SMS message inboxes. While you can do everything above on the Twilio website this app works with just API keys so you don't need to log into the website. It is free to use, there are no ads and the app doesn't collect any usage information from you on its own. It is sandboxed to only have network outbound access and a keychain group to store the auth key.

This content is not associated with or endorsed by Twilio.