The Google Play Store is now starting to show 'free' and 'premium' filters for some users. It is currently unclear as to how widespread the features is, although it is clear it is not showing up for all users. Likewise, it is does not currently seem to be in effect for all searchers made by those who have access to the filters. For those users it is showing up for however, the new filters make it a little easier to find a suitable app, at a suitable price point.
This is different to the 'paid' and 'free' apps that show up as part of the 'Top Charts' feature on Google Play. As the difference is the new free and premium features are more designed to refine searchers already underway by a user. So while the Top Charts option will narrow down the apps which Google Play considers to be the best free and paid-for apps, this one will be more useful when the user is looking for a specific type of app. Say for instance, a file sharing app. As once the 'file sharing" term has been searched for, the free and premium option will allow the user to instantly cut paid (or free) apps from showing up on the search results list.
Search filters themselves are not new as they did start to roll out properly back in June of this year. At the time however, the selection of filters was more limited to key aspects related to the search term. For example, searing for "food" would return filters including "delivery" and "recipes." Needles to say, filters which likely do not help a user searching for "music downloader." So while the existing filters are more of a 'smart filter' type, it seems the free and premium filters are likely to be more generic ones which will show up for all apps – as it is likely most, if not all app searchers will return both paid and free versions. This is of course, providing Google does roll out the feature on a wider scale. As at present, it is very limited in its reach which usually suggests it is still firmly in a testing phase of deployment. It is also worth noting that a 'no ads' filter is also showing up for some searches. Although it is currently less clear whether this is as new as the free or premium filters and especially considering the 'no ads' filter seems to be far more prevalent at the user level already.