[Joona]

For tagging apartments as "I don't like it", you could create a browser extension that automatically hides them. That aside, I think dirktheman's comment is relevant; I don't think the data you want is useful for most other users.

[get]

I never use browser extensions because of the security and privacy problems.

When you say 'most other users' - can you quantify that? If for example 99% of the world population does not care, that would still leave me with 76 million people who do care.

[jaredsohn]

If you build it yourself for yourself, you should be able to have some confidence re: security and privacy.