Do Mozilla Open Badges Only work on BackPack

Question

I was going through the Mozilla Open Badges and the idea is to integrate it with my badge issuing system.

I do understand the following going through open badge api and docs :

1. I can create my own badges and use Badgekit to do it
2. I can issue badges using the issuer API

My question is :

1. Can the badges only be displayed and collected in Mozilla Backpack
2. Are there ways to write Badge Creators using java already available and if not can it be created ?

Thanks, Abhishek