First we downloaded the java version of the map, created by GTawesomesauce,
and a group of 3 played in it opening it to LAN so several people could explore and work together in the map. We also downloaded and installed a lucky dog plug in. The participants soon learned that you really do need plenty of torches in a jar world or the creepers will soon destroy much of your bottles.
This is map is great fun and we had so much fun with it that our friends with the PE version of minecraft were extremely jealous. After a little searching, I found that someone had ported World in a Jar to a PE version and after a little tinkering we were able to download and open that world to our group. This meant that everyone could play together because the Minecraft windows 10 and tablet and phone versions could all enter the same shared world.
If you are looking for something different and challenging, World in a Jar is an excellent choice. We have created and played in several copies, because each member of our group of 10 wants to be the 'owner' of the world and control the rules of play for their world and still have the fun of a team.