Out to Eat with Kids is my go-to website (and app). It's nationwide and you can sort by zip code and day of the week (don't forget to click to the next 10 results if applicable). There is also an option for you to report an error.
Here are the area deals that I know of, please let me know of any additions or corrections.
Applebee's Niles location
0.99 Kids meal
Beef o Brady's
Chili's Boardman in front of the Southern Park Mall
sign up for their email, sometimes the coupons sent out include Kids Eat Free and once in a while they host a father/daughter date night
El torero - Warren & Cortland
MONDAYS Kids 12 and under eat free
Los Gallos Mexican - Austintown, Boardman, Howland, Struthers
website has coupons (there is currently a Kids Eat free one)
WITH THE PURCHASE OF 2 ADULT ENTREES
(2 KIDS PER FAMILY AGE 10 AND UNDER)
ALL MAHONING COUNTY LOS GALLOS LOCATIONS
Kids eat free on Thursdays
WEDNESDAY & SATURDAYS
Kids Eat Free with purchase of adult entree 3pm-9pm.
Plaza Azteca Niles
SUNDAYS & MONDAY kids eat 1/2 off
Kids 3 and under eat for free, kids 4-7 eat for $1.99, and kids 8-12 eat for $3.99 all day
watch mail for coupons!
Steak 'n Shake - Boardman, Niles
SATURDAY & SUNDAY SPECIALS:
Kids Eat Free all day. One free kid's plate per $8 spent.
Salsitas -Boardman, Austintown, Youngstown
Kids 12 & under eat free with adult meal purchase.
Smokey Bones Boardman
KEF deal previously mentioned, not sure if still available
Stoneyard in Niles
Sundays kids meals are 1.99
Kids eat for free all day, limited to one child per adult entree purchased
The Eastwood Mall's sale page sometimes lists current specials for restaurants on the complex's property.