Is EssentialsPE only a package of lot of existed plugins from many authors ? Did you (dev group) give credit for every plugins/ideas parts from others ll be mentionned ? I see so many thread that you wrote like: "I ll put it in EssentialsPE !" exemple -> http://forums.pocketmine.net/threads/invincible-god-mode-for-ops.273/page-2#post-44330 ... and there are so many others like that from many existed plugins !
@iksaku knows much more than me about the logistics of the plugin but I can probably help you somewhat. EssentialsPE is in no way a culmination of plugins. Yes, some of the features used inside EssentialsPE occur in other plugins. However, our main source is Essentials for Bukkit (which we will credit) and only ideas which can't be sourced from there or inside our team would make additional credits necessary. I think further questions regarding this would be better addressed on our repository: https://github.com/LegendOfMCPE/EssentialsPE.
[I know it's too late xD] Well, EssentialsPE is a plugin that let you have most of the Bukkit Essentials on PocketMine-MP, I'm trying to port has many features as possible to EssentialsPE from the original Essentials, I don't copy any code from other PocketMine-MP plugins, and I don't copy any ideas from here... The permission to port it was accepted by the Essentials Developers and there's no other think I need for it.