hi! I’m looking for some very simple hiragana ebooks meant for japanese children so it will be easy(er) to understand.
okay I found some “childrens” books but those are still too advanced - I’m looking maybe for kindergarden-level stuff for those “just beginning” to read (many pictures, small sentences, etc etc)
Hey! I havy many books for japanese childrens, but is not e-books. So I found The Little Prince in japanese, and this book is really simple. Maybe u can read it!
http://www.alz.jp/221b/aozora/le_petit_prince.html
Good luck 
「おとなのひとは、ボアの絵なんてなかが見えても見えなくてもどうでもいい、とにかく、ちりやれきし、さんすうやこくごのべんきょうをしなさいと、ぼくにいいつけた。」
上の文章は、下のように漢字で表記されていないと、かえって読みにくいのではないでしょうか？
とにかく、地理（ちり）や歴史（れきし）、算数（さんすう）や国語（こくご）の勉強（べんきょう）をしなさいと……
サン=テグジュペリの、すばらしい作品だと思います。
The Little Prince, Winnie the Pooh and the Harry Potter series are all simpler-than-average books translated into just about every language, including dead ones. I look out for them for all languages I learn.