Having no direct experience with any of these tutor-finding services, I cannot offer a personal recommendation, but will provide these links in the hope that they maybe helpful to students wanting to find a tutor, and to teachers wanting to offer their skills to students needing tutoring.  

There are many other tutor-location services available online, but the most direct method might be to ask your child's teacher or school administrators to recommend a local retired or moonlighting teacher who could take on your child as a client.  And, many teachers are willing to work individually with a student before or after school.                                                    

If you decide to find a tutor through an online service, be sure to verify the tutor's qualifications and make arrangements for a location for the tutoring sessions where you can supervise your child's safety.

"Caveat Emptor"                    --Mrs. Ellis
USA:  "Search for and hire the perfect private tutor today"
 Private Tutor Directory Service that helps match students to tutors. Search by location, grade level, and/or subject to find a tutor near you. Tutors and potential clients negotiate their own arrangements.
Colorado Tutors Based near Denver, CO, this appears to be a not-for-profit organization formed by a group of educators.  "Tutoring kids from kindergarten right up to college, and even special education students who may struggle with a learning disability..."
 University Tutor  Another matching service promising to connect students to "a great tutor in your area."
United Kingdom: 
Based in the UK, this service helps students find a nearby tutor to help improve academic performance, skills and knowledge.  Most available tutors are in England and Wales.
Nov. 15, 2012