Follow up after a co-op position?

Hey Guys,

I recently finished a co-op position that lasted 8 months and overall it went very well. I left on good terms with my managers and co-workers and have been in touch with a co-worker.

I was now thinking of touching base with my manager but not sure how to go about it?

My e-mail so far consist of asking how everything is going and if the software I developed is working well.
Is this ok to ask? Has anyone done this before?