nostr:npub1k5f85zx0xdskyayqpfpc0zq6n7vwqjuuxugkayk72fgynp34cs3qfcvqg2 makes a similar DIY device that is fully open source named BTClock

They get harassed at launch by Coinkite

It goes well for a while, then Coinkite takes down their Github by claiming trademark infringement because BTClock is too similar to Blockclock