As far as I can tell, Google does not provide a mechanism for searching for completely free apps in Google Play. When using the
FREE filter, you get both completely free apps and apps with in-app purchases, where some elements are unavailable without paying, so they are not completely free. In some categories, most of apps' content is available via in-app purchases only, so it's misleading to have such apps in the free list.
In the Google Play application, I am able to detect that an app isn't completely free If I open the details page and see "In-app purchases" on the left side. It is inconvenient having to open every app page just to verify this, but at least it's a workaround. Is there some way to include that criteria into the search function?
Additionally, when searching Android apps through a desktop browser (Chrome) instead of the Google Play app on the device, "in-app purchases" does not appear to be displayed, even in the details page of the app.
The question: How to detect or filter out apps that are not completely free, on Google Play?