Oi LucasDonaiSfalcin, sim eu falo português, mas aqui estou trabalhando, né? Então tenho que falar inglês!
You can add several "gnome like" apps if you add on your bblayer the meta-gnome. And you I know some people worked to get apt-get available in the final image of a distribution created by yocto project.
But, keep in mind this is a feature of a distribution created using YP, it´s not the the default configuration. The keyword you want is "package feed". http://www.yoctoproject.org/docs/latest/poky-ref-manual/poky-ref-manual.html#package-feeds-dev-envir....
It´s not easy, or simple, or fast to implement or keep the server updated! If you need help on this matter, please, use the YP mailing list.
However, I think you don´t need this "feature" on your final product. You are on development phase, and in this phase you miss some packages that are not in your image. What I recommend is that you create, and keep track, of your own image. That one that will be on your final product. And then add the packages you miss during the development, and generate a new binary.
Think that, for example Ubuntu, it must have a program like apt-get, because it´s the intention of the product. But a, for example television based on kernel, maybe you don´t want to provide a way to customer update the interns. Or pay the price to have a package server up-to-date.
