I have been using this solution for two and a half years. 

I have been using this solution for about a year.

I have been using this solution for close to three years.

I've used the solution for a little over a year.

Our company has been using LeanKit for about two years. My experience has been less than that. It is newer to me. I have been using it for almost a year. 

I have been using LeanKit for about nine months.

I have been using LeanKit for about eight months.

We started using this solution a year ago. We opened it up for users outside of our group around six months back. 

We've been using it for about four months.

I have been using LeanKit for four months.