How exactly do you activate this?
EDIT: Doesn't work on iOS 8, nevermind
I'm going to go ahead and answer this anyway, so if anyone is on iOS 7 or below they can see.
Netatalk simply installs and enables Apple filesharing. There is no preference setting, it's simply "on". Someone later created a Netatalk Flipswitch though so you can turn it off. I leave it off unless I need to use it. That way no one can try and access my phone via Netatalk.
Anyway, it's just like you would connect to a share from your Mac.
Your phone appears in shared items in the Finder and you can connect to it like you would another Mac. It asks for your username and password. You can either use root or the other SSH default user with less access. This is why it's important to SSH in and change the passwords before you install Netatalk, because the passwords you change them to in SSH are the ones you use to connect to your phone via Netatalk. Netalk, if it's on works via WiFi. I also assume that it could be accessed via cellular if someone knows your IP. So, if you've left the standard passwords unchanged and Netatalk running…well don't say no one warned you about changing the passwords.
Enter the password and the phone loads on to your Desktop like a shared drive. From that point you can use it just like you would any other share or drive. You can open and save to it from other programs, you can copy files back and forth and you can directly edit files on your phone.
This, to me, is much simpler than trying to use Terminal to get stuff done. Or an FTP app.