LMS with Manual Assignment Grading and Custom Rubrics

[ Moved to the Fixing WordPress sub-forum. ]

Hello,

I have half-developed a custom LMS for my wife’s business with WordPress as the backbone.
(For the past month, I’ve been looking for a possible substitute solution.)

I’m now wondering if there is an LMS plugin out there that would be a suitable replacement for what I’ve created. It’s not going to be an easy switch, but I’m more interested in a 3rd Party solution to support this that I could pay a nominal annual fee for their product, instead of me having to get in to the back end and continue to build code. Here’s the deal breaker though, the software MUST have the capacity to manual grade assignments that get submitted by the students.

Here’s a few more details:

I’m loving some of the additional features that are being delivered by some of the other products out there available, but I’m looking for something specifically that will allow direct interaction between the instructor and students. We manage an online training venue, which requires our students to write up their answers. There are no quizzes per se. So the instructor needs to be able to manually grade and give feedback on the assignments that are submitted, and then mark assignments as completed or not.

I’m all ears. Thanks for any suggestions. If someone was interested in partnering with me on finishing this, I’d be interested in the option as well.