I have somehow managed to get it to work. I'd like to write a quick and simple guide for those who are having the same problem:
This also may work on other mod packs. I think it will, in fact.
1) Okay, first, download MAtmos from this website:
http://ha3.eu/public/mc-mods/matmos.php#install if Ultimate is up to date with the latest Minecraft version, or(in my case) download it from
http://ha3.eu/public/mc-mods/collections/matmos/bin/ (make sure you download the right version, in my case, it was
MAtmos_r21__1_4_6.zip).
2) Open the zip. It contains some files, as you can see. The files we need are folders called
matmos,
mods and
resources. Go to where your Ultimate(or the modpack you use) is located(in my case, it is
D:\FTBmodpack\Ultimate. Drag and drop
matmos and
resources folders into it.
3) Then, in the zip, go to
mods folder. Here you can see a zip called
matmos_packaged. Drag it somewhere from the zip(for example, on your desktop)(and don't unzip
matmos_packaged!!!). Open your FTB launcher. Select the modpack you use(for me, it is Ultimate). Make sure it is the modpack you dropped
matmos and
resources folders into. Click on
Edit modpack button. Click on
Add mod. Find and select
matmos_packaged. It should appear in
enabled mods.
4) Launch your Modpack now. MAtmos should now be in your mods list. Go to your SP world/MP server. MAtmos should work, if you did everything like I told you.
Should I make screenshots? Or is this guide allright?