Sync with iPhone?

OK, I bought this to replace a delorme explorer.  I used that as a standalone.

my question is this.  can I sync this with my iPhone to do the texting with instead of using the onscreen?  What app do I use?  I use Garmin watches and use the connect app.  can I send texts through the iPhone using the 66I?

I should add, I cannot seem to sync the 66I to my iPhone using the connect app.  Not sure why.