I have ADD and LOT of trouble sleeping and staying asleep. Recently found a solution that makes a big difference. I turn in early, knowing I won’t sleep immediately, and take a tablet to bed with me. I use the TuneIn app to play audio dramas, Blindy TV or audiobooks. My tablet is a Kindle, so I can also have it read to me. Because I can do this with the screen off, there’s no blue light. I’m lying in the dark with my eyes closed, listening to something that takes my mind off whatever anxiety or racing thoughts I’m experiencing. Lately, instead of being frustrated that I can’t fall asleep, I’ve been annoyed that I fell asleep halfway through the Dimension X episode or the chapter I was listening to. If I wake up in in the night (which I still do), I go back to sleep much more quickly with the same practice. For a 7 year old, you might want to just use a Kindle or Nook and let it read to him in in the dark, since most of the audio dramas aren’t written for children that young.