Any progress on this?

Yes yes new default color scheme because I can not see dark colors on GBA very well.
Only in light room or outside somewhere in nature.

Papu was just example.
It was just quick and not original brainstorming...
Just for showing. That FatTracker2 name is better than.
Fatass...
pAPU is NES soundchip by Nintendo BTW...

You can already change the colors, so what you want is a new default color scheme?  That's not really on my list of priorities.  Also, out of respect to the original programmer I'm not likely to change the name drastically.  I've been toying with calling it "Fat Tracker 2", but we'll see.

So far I'm interested in the important usability features.  Mainly everything iLKke mentioned, to make it easier to place notes and hear the changes you are making.  I hope to implement a "keyjazz" feature (allowing you to hear the notes as they are placed, but I'll have to see how his playback routine would jive with that.  For now, to avoid biting off more than I can chew, I'm going for the simple stuff (which also seems to be the most important).

On a side note, why the hell would I name it PAPUTracker? What does that mean?

I don't see the need to change the colors.

the ability to preview notes like in LSDJ without having to play the track.

When I press select there is menu. And than I want see what I choose.
So I want have inverted row - actual item.
No plazma row...

+ maybe light color scheme more visible on GBA LCD... More contrast colors...

+ Change name "Fatass" to another name...

For example:

PAPUTracker
RhythmicTracker

etc etc etc etc

make it easier to delete notes, instead of having to go all the way down past C-3?

make it so it remembers what the last note you put in was, so you don't have to go all the way up to whatever your putting in?

any track in this soft to hear?

Here are a few ideas, together with comments.
Mostly usability improvements, not magical features

general:

    -song loop position not working
        it's in but doesn't work

    -ability to mute/solo channels
        can't believe you can't do this. perhaps I just couldn't find it?

    -song should keep playing when you enter effect editor
        so you can hear what you're doing while you're doing it

pattern editor:

    -b+left/right - move 8 (or 11) steps up/down
        so you can get to the desired step quickly

    -a+b+up/down - prev/next pattern
        so you don't have to jump to the sequence editor and scroll through it

main menu:

    left/right - prev/next screen (jump 11 rows)
        practically jumps to the next/prev page of the menu, since it's a big menu

Also, the noise channel seems to be kinda crap. Not sure what can be done about that

After looking over the source for Fatass tracker, I've somehow got it into my head that I could probably add a few needed features.  There's no promise in this, but if I was going to do an updated or modified version of Fatass, what features, changes, etc would you like to see?