BombaStompa is a time-stamping service built on Ethereum. This service allows you to prove that some file or any data existed before some time point (time-stamping). The time-stamping is only accurate to ~ ± 20 sec as the timing data is dependent on the ethereum network.
This is a monorepo which includes both Ethereum contracts as well as a web interface for BombaStompa. I'm not a cryptographer nor a security engineer, this service might not be secure!
To use this service you must be using MetaMask. Each hash entry is linked to a name you give it while submitting it and to the Ethereum account you used to submit it; thus meaning that in order to retrieve a given hash entry you must use the same name and Ethereum account used to submit it.