I have successfully completed the trailhead challenge in my Dev org which is as follows:
Create a test harness app and component
Let's get set up for doing development right now. You'll create a test harness Lightning application, and add a simple component to it. Then you'll verify that you can see changes in the component.

• Create a new Lightning component named myFirstComponent
• Add this static text to the component: I solemnly swear I know JavaScript
• Create a new Lightning application named harnessApp
• Add myFirstComponent to the harness app with this markup: <c:myFirstComponent/>
• Click the Preview button and verify your text is displayed
• Make a change to the static text so it reads: I am proficient in JavaScript
• Click the Preview button again and verify your change is displayed

When I try to verify the challenge, it displays as error as follows:
Challenge Not yet complete... here's what's wrong: 
The 'harnessApp' Lightning App does not contain ''.

I am unable to understand the error. Anyone who received similar kind of error and were able to proceed further, Please help me with this.

The following won't validate, but won't pass the validation in this trail.  Quantity field is howver using the correct field.  Thoughts?



<aura:component>

<aura:attribute name="item" type="Camping_Item__c" required="true"/>    
    <ui:outputText value="{!v.item.Name}"/>
    <ui:outputCheckbox value="{!v.item.Packed__c}"/>
    <ui:outputCurrency value="{!v.item.Price__c}"/>
      <ui:outputNumber value="{!v.item.Quantity}"/>
            
</aura:component>

Sales Managers have asked for an at-a-glance solution to see completeness on leads. Create a helper formula field that looks at 5 key fields on the Lead object and evaluates their completeness, then a second formula field that references the helper formula and returns an image.

>The helper formula field should be on the Lead object with a name of 'Lead Quality Helper' and a resulting API name of 'Lead_Quality_Helper__c'.
>The helper formula should be of type Number.
>The helper formula should evaluate the following 5 fields: Email, Phone, Company, Title, and Industry and return 0 if blank and 1 if not blank. >The formula should then add all the values together to return a total value.
>The image formula should be on the Lead object with a name of 'Lead Quality' and a resulting API name of 'Lead_Quality__c'.
>The image formula should reference the helper formula, and return an image based on the number returned by the helper formula. The helper formula should be of type Text. Note: All of these images are already available in your Developer Edition.

1 = /img/samples/stars_100.gif with alternate text '1 star'
2 = /img/samples/stars_200.gif with alternate text '2 stars'
3 = /img/samples/stars_300.gif with alternate text '3 stars'
4 = /img/samples/stars_400.gif with alternate text '4 stars'
5 = /img/samples/stars_500.gif with alternate text '5 stars'

If none of the fields are filled out, the default should be /img/samples/stars_000.gif with alternate text '0 stars'.
The 'Lead Quality' formula must be added to the Lead Layout page layout.

ok so im having trouble on this challenege on trailhead. im confused what it means by helper formula, like how would we create a helper formular? also how would we create a image formula?

thanks if anyone answers