structured data for free SoftwareApplication - structured-data

Question

I have structured data for SoftwareApplication in HTML page like this:
https://developers.google.com/structured-data/rich-snippets/sw-app
But if I check my structured-data:
https://developers.google.com/structured-data/testing-tool/
Its have warning:
offers: missing and recommended
My Android application is free. How can I write this for free App?
<div itemprop="offers" itemscope itemtype="http://schema.org/Offer">
Price: $<span itemprop="price">1.00</span>
<meta itemprop="priceCurrency" content="USD" />
</div>

Answer 1

For the Offer, a price of $0 is valid and what Google SDT expects in this case.
<div itemprop="offers" itemscope itemtype="http://schema.org/Offer">
Price: $<span itemprop="price">0.00</span>
<meta itemprop="priceCurrency" content="USD" />
</div>
If you don't want to show the price, you can use meta tag again for price.
<div itemprop="offers" itemscope itemtype="http://schema.org/Offer">
<meta itemprop="price" content="0.00" />
<meta itemprop="priceCurrency" content="USD" />
</div>
In general though, Google wants you to show the price to the user since it might create misleading or deceptive search experience. See policy:
https://developers.google.com/structured-data/policies#non-visible_content_and_machine-readable_alternative

Answer 2

There's a NEW SOFTWARE DATA TYPE (BETA).
The new software app data-type allows you to use offer type to set if it's free or not, now and here the rules are different, please refer to the following link for more info and warnings for not being "banned":
https://developers.google.com/search/docs/data-types/software-app
there's a difference between free app and a paid app that is free for a limited time:
If the app is free of charge, set offers.price to 0. For example:
"offers": {
"#type": "Offer",
"price": "0"
}
If the app has a price greater than 0, you must include offers.currency. For example:
"offers": {
"#type": "Offer",
"price": "1.00",
"priceCurrency": "USD"
}
regards.