Hello Slobodan,
Well, AAL is not too much like Java Bridge, though there is some code shared from it.
Altbridge, or Java Bridge are designed for people just coming into Java, whereas AAL isn't. Not that you can't use it when learning Java, but it will be harder to learn comparatively.
One thing I would suggest, is to take the Intro to Java course on
udacity.com . You can take their courses for free, though you can pay them (I forget what the difference is, I believe when you pay, you get instructor led classes, as opposed to taking scripted lessons). This will be necessary for you to really be able to write apps for Android. (not necessarily at udacity, I just chose them because my girlfriend took it, and it helped her a lot).
As far as support for AAL, I use it in my own projects, so it's not going anywhere anytime soon. I had been thinking about creating a group for it, just hadn't gotten around to it yet :). But now I've finally created a group for it, it's here:
https://groups.google.com/forum/#!forum/aal-support BTW, you don't have to download anything from bitbucket to use it. You just have to add a line to your project's build.gradle file. There are usually 2 of these in a project, you want the one in the folder named "app" (it should have an android section in it).
I have a samples project that I had been working on, I'll try to get that project into a more presentable shape in the next week or two.
If you have any other questions on it, please post them on the new aal support group (thanks for giving me the push to get it created :P ).
Ryan