The Play Store already has a "Contains Ads" label for apps with ads. Preventing users from searching/filtering with this label is consumer-hostile.

Here are a couple of third-party workarounds:

- KPlaySearch (https://playsearch.kaki87.net) lets you search the Play Store and optionally filter by whether the app is free of ads and/or in-app purchases. Source code: https://git.kaki87.net/KaKi87/KPlaySearch

- Aurora Store (https://auroraoss.com/download/AuroraStore/) is an alternative Play Store client that works without a Google account and without Google Play Services. Its app search allows filtering by whether the app is ad-free and/or dependent on Google Play Services. Source code: https://gitlab.com/AuroraOSS/AuroraStore