Yes, it's a little different. You can't use the element IDs in the same way because of how they've structured their page, and they don't have an import list function, which is what the OurGroceries command uses to add items. To add new items to the zip list you need to use their add item form field instead.
Are you familiar with how to use RoboB's "show" action with mouse tracking to find element IDs, etc.? That's a pretty useful way to inspect the page and find what you need. It's how I figured out the following.
The add item field's element ID is "zipbox_command". However, in order to actually submit your new item, you'll then need to emulate clicking on their "Add Item" button. If you roll over that button, you'll see that it's defined with an Input tag, index no. 6. You then need to use RoboB.Click to simulate a mouse-click, rather than using RoboB.Submit as we more commonly do.
The list itself is also formed differently than Our Groceries, which means you can't check existing list items by finding the right element ID. Instead you need to look for a pattern in how they are defining grocery items. They do this with span tags, class=iname. To find that pattern, we rely on ye olde regex.
Below is code that should work for you to add a new item to your list, including checking whether the item is already on your list before adding.
<?xml version="1.0" encoding="utf-16"?>
<commandGroup open="True" name="robob ZipList high priority" enabled="False" prefix="" priority="5" requiredProcess="" description="">
<command id="617" name="open list" enabled="true" alwaysOn="False" confirm="False" requiredConfidence="0" loop="False" loopDelay="0" loopMax="0" description="">
<action>
<cmdType>RoboB.Select</cmdType>
<cmdString>ZipList</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.SetWinSize</cmdType>
<cmdString>800&&600</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.Navigate</cmdType>
<cmdString>http://www.ziplist.com/mylist/YOURLISTNUMBER</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.Show</cmdType>
<cmdString />
<cmdRepeat>0</cmdRepeat>
</action>
<phrase>prepare, start, ready</phrase>
<phrase>robo browser, our groceries, grocery list</phrase>
<event>VC.Loaded</event>
</command>
<command id="695" name="Add Item" enabled="true" alwaysOn="False" confirm="False" requiredConfidence="0" loop="False" loopDelay="0" loopMax="0" description="">
<action>
<cmdType>RoboB.Select</cmdType>
<cmdString>ZipList</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.ElementRegex</cmdType>
<cmdString>span&&class=iname>{1}&&False</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.GetText</cmdType>
<cmdString />
<cmdRepeat>1</cmdRepeat>
</action>
<if ifBlockDisabled="False" ifNot="False">
<ifType>LastActionSuccess</ifType>
<ifParams>&&</ifParams>
<then>
<action>
<cmdType>TTS.Speak</cmdType>
<cmdString>You already have {1} on your list</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>VC.StopMacro</cmdType>
<cmdString />
<cmdRepeat>1</cmdRepeat>
</action>
</then>
<else>
<action>
<cmdType>TTS.SpeakSync</cmdType>
<cmdString>Processing</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
</else>
</if>
<action>
<cmdType>RoboB.ElementByID</cmdType>
<cmdString>zipbox_command</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.SetText</cmdType>
<cmdString>{1}</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.Wait</cmdType>
<cmdString />
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.ElementByTag</cmdType>
<cmdString>INPUT&&6</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>RoboB.Click</cmdType>
<cmdString />
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>TTS.Speak</cmdType>
<cmdString>{1}, was added to your list</cmdString>
<cmdRepeat>1</cmdRepeat>
</action>
<phrase>don't forget, remember, I need, We need, remind me</phrase>
<phrase>to</phrase>
<phrase>buy, purchase, get, pick up</phrase>
<phrase optional="true">some, more, some more</phrase>
<payloadFromXML phraseOnly="True" use2partPhrase="False" phraseConnector="by" Phrase2wildcard="anyone" optional="False">groceries.xml</payloadFromXML>
<phrase optional="true">please</phrase>
</command>
</commandGroup>
You'll have to take the same exploratory approach to figure out how to re-do the other commands as well, but hopefully this provides a helpful start for you.
cheers