A website which would get blocked instantaneously. Russia has an extensive censorship toolset available. They've blanket blocked a whole range of Cloudflare IPs at some point because they wanted a certain website behind Cloudflare shut down and didn't care about the collateral damage.
Of course, such a block is easy to circumvent with a VPN, but if you need a VPN to access it then the service is essentially unavailable to non-techs, greatly reducing its effectiveness.
There is a website[0] and I don't know why they didn't just launch a similar web app. Running on Google's appspot.com, the website would probably be dealt with the same way the apps were dealt with. No big hosting company (Amazon, Google, OVH, you name it) wants to risk being banned from the Russian internet, after all. A TOR hidden service would probably survive attempts at censorship, but at that point the whole effort is probably not worth the effort because you're not reaching many people locking the information behind TOR.