Getting a Blackberry to work with a group calendar

So I created a group calendar on gmail so that our work team can all look at the same appointments and dates. It’s working on our Android phones and iPhones, no problem. However, my boss’s blackberry is not cooperating. It’s been 4 years since I traded in my BB bold, and I don’t know how to get it to work.

He has his work email and a dummy Gmail I installed both working on that phone. Since he’s technologically inept, I want to find a way to make them seamlessly integrate, so that: A) anything the team adds to the calendar, will show up on his Blackberry; and B) any thing he adds to the local Blackberry calendar, will automatically be added to the google calendar.

Any suggestions? Obviously cheaper is better, but we can afford a paid app if it comes down to that.

I haven’t touched a Blackberry for a year or so, and didn’t really know that part of the world anyway…but an important question before anyone can answer:
What Blackberry is it? Specifically, is it before or after BB10?

BB10 was a complete rewrite of the OS and the UI. The latest ones support most Android apps, which makes it a little easier to find solutions.

I’m 99% sure it’s a BB10 device based on the age, but I will double check that point. It’s my understanding, however, that Android “support” involves some sort of emulation of a Gingerbread ROM, which really isn’t all that helpful for calendar integration; it would need to be something which can be used as seamlessly as possible.

It doesn’t HAVE to be a google calendar, if something else works better.