Tick Tock, The Bedtime Clock is a simple travel clock that lets your young child know when it is OK to wake up in the morning and when it is time to go to bed by using a drawing of a sun and a moon to indicate day and night. I recommend setting up guided access to lock out the home button and settings button if your child can physically reach the device.
I created this app for my son when we were on holidays because I couldnt find anything like it in the app store. I hope you find it useful as well!