I'm looking for games that are appropriate for kids age like 5-8 roughly.

I know about No Thank You, Evil and some other more mainstream ones but I'm also curious about indie games that are available that are aimed at kids or would be kid appropriate with little to no hacking.

To save myself from having to write out an essay, I'm just gonna link you to my post on r/rpg about the game Hero Kids. In said post, I also mention 2 other games, the one you mentioned and Amazing Tales (which may be a good fit for you, but I'm not a major fan of it). I'll give you some quick highlights below all the same though. Should be an excellent fit for you!

• Very easy to learn and get to playing, you can read the book in about an hour and immediately start playing.
  • D6 system working on target numbers.
• Lots of ready made materials.
  • Adventures (I believe we are up to 13 or so now).
  • Maps and Mini's (paper ones, but that's a plus since your kids can color them).
• Inexpensive (especially on sale), though I do recommend the "Everything Bundle" which is at an increased cost, but still well within most peoples budgets (~$6 vs ~20).
  • Speaking of the "Everything Bundle", I do mean EVERYTHING past, present, and future!
• Easily can adjust complexity by adding new elements which can keep the game fresh and interesting. The game grows as your kids do!
  • A happy side effect of this is that if you choose to transition to a system like D&D in the future, this game will allow for that with relative ease.
• Friendly and helpful community, including the creator who is active in said communities.

The post has a lot more detail and such, so I do suggest you give that a read. If you have any questions please don't hesitate to ask, I'm happy to help! :D

I think it would be easy to modify Inspectres to fit the age group and keep the rules aspect squarely on the GM's side. This might be one of the mainstream RPGs you alluded to earlier, in which case - whoops! sorry! I just love InSpectres so much.

Scales and Tales! A really good RPG designed with kids and beginners in mind!