Set a time limit with a timer for the ipad.

I had this problem when I was younger and my mother killed two birds with one stone with how she did it. She made me start off with a certain amount of time in a book I could use for the computer. I can't remember now probably 2 hours. At the end of the week she would add an extra hour or half hour like an allowance. If I did extra chores to help out around the house I would get "paid" hours extra to add to my computer time. If I ran out of hours that was it, I couldn't use it until I earned more hours. I HATED it, but it did get me to help out more and reduced my computer times

We've used ourpact to set schedules for all the kids iPads for about a year. It follows the schedules you set and automatically removes their apps and then puts them back. My kids iPads are set to be off between 9am and 4pm and then again between 7:30 pm and 6am. You can also use the app on your phone to grant or remove access anytime. It's free

http://ourpact.com/

Build up other FUN leisure skills...do a set limit for IPAD rotated with interactive time (slowly decrease iPad time and expand interaction/skill time)...do first X, then iPad, only give iPad as reinforcement (cold turkey otherwise)... Use an actual timer that doesn't shut off until turned off...

This sounds bad, but I never set time limits or restrictions with the iPad. My daughter use to play with it all the time I stopped adding new apps and she eventually got bored of it. She only uses it now for YouTube kids unless I play the games with her. Sorry not much help just thought I would share.