Thanks for your post! I can tell you that it is true that the Free version may contain ads/notifications. This is how we can support a Free product for all Android users.
However, you can control the notifications from the app in a pretty fine-grained way, even in the Free version.
If you wish not to see ads at all, upgrading to a paid version will remove them :)
While I'm here, you might also find this recent blog post interesting, it's about the recent growth in Android ransomware: https://blog.avast.com/protect-your-android-from-ransomware
Thanks for checking out Avast and feel free to let me know if you have any other questions, we're here to help!