messages app on iPhone

There are settings shared across all capable devices to allow Continuity use fairly easy.

• How to forward SMS/MMS text messages from your iPhone, to your iPad, iPod touch, or Mac - Apple Support

https://support.apple.com/en-us/HT208386

iMessages can share between iDevices and Mac ~ and then some.

• Use Messages with your Mac - Apple Support

https://support.apple.com/en-us/HT202549

• Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch - Apple Support

https://support.apple.com/en-us/HT204681

Sections and additional details are covered in second link.

Good luck & happy trails!

⛵️🎣🌻🌤🌎🌿🤖☺︎

The application is (iMessage) is already within iOS for iPhone; settings allow

that to connect and work with Mac Messages. ~ An answer is to use both

of those iOS/macOS applications to bridge the gap; answer: learn settings.

Can't see as I could spell this out much better; short of providing hard copy.

Take care & good luck!

🌞🌿🎣🌤🐢⛵️🐟🐌📬

On the Mac it may be called just Messages, in the Applications folder, the iPhone version won't work on a Mac anyway. :)