I'm leaving my current employer in two weeks, but have an excellent relationship with them and am somewhat emotionally attached to a project that I have developed over the last couple of years.
They've asked me if I'd be willing to contract with them to continue supporting that project.
I was thinking of proposing a monthly retainer that would assure them 5-10 hours of support, including answering support E-mails, fixing any bugs, and small stability enhancements and feature tweaks.
I haven't ever seen any mention of software developers contracting under retainer; is this done? If not, is there something that makes it is a bad idea?

