How can I figure out if an application actually put their data on blockchain?

For example, revain (review platform, It claims to be a decentralized review platform on ethereum blockchain, but I highly doubt it because I didn’t notice any gas usage.

Is there any tool could help me figure out if a application actually store data on the chain? Application data, not the token issue/sell/buy data

Submitted March 09, 2018 at 12:48AM }
via reddit