[Solved] So many ways to deal with different android DPI/Resolutions.... Which?

Hi forum!
Recently i published my 2nd game in googleplay and i made a terrible mistake!

I programmed with the resolution of 800x600 in mind.
So The windows size starts at 800x600.

Later i use the code in annex to render the main menu.

It seems that, people with a small cellphone but with a high resolution will see the buttons very small.

So i went to libdgx chat researched, then went to google and found thousands of ‘solutions’ for me to test what suit me better. But which one of them is the correct one?
How do you guys do it? I decided to make a topic because i know you guys will able to tell me what direction should i go!

This is the game i published :

It uses box2d , idk if does matter because of “pixels per meter” stuff.

By the way, i did try using Fitviewport and it causes black bars.

http://www.java-gaming.org/index.php?topic=25685.0


http://pastebin.com/baQkGJ67