Yandex.Metrica is a website analytics platform owned by the Russian company Yandex. It provides free analytics services, including features like traffic stats, event tracking, purchase funnels and even session replays and heatmaps.
As mentioned in their own FAQ, one of the reasons why the platform is free is because it enables Yandex to collect massive amounts of data to feed into machine learning systems. Not only can this lead to huge privacy and GDPR issues but it is also unclear what the data is used for.
Self-hosted platform with stats, heatmaps, session recordings and more. The dashboard has been recently rebuilt from scratch and it receives frequent updates.
Self-hosted and open-source, previously known as Piwik, it also has a cloud offering. Unforunately the heatmaps and session-recordings are not provided in the open-source version.
Does come with core analytics functionality and heatmaps but no session recordings. The platform feels a bit basic/outdated compared to Yandex.Metrica.
The platform was recently updated to a new version, might be worth checking out. Unfortunately it doesn't provide the indepth analytical quantitative data that Yandex.Metrica does, being focused on the qualitative data.
There is a community-managed list of analytics platforms on GitHub called Awesome Analytics (doesn't include all analaytics platforms, but it's pretty comprehensive).