Probably late summer / early Fall! Want to make sure the developer experience is high-quality at time of open-sourcing, but we're testing now / onboarding artists in a private beta.
Very similar from a meta-transaction standpoint, but ours is simple and centralized (albeit trustless due to the tx signing model). This is much cooler!
https://blog.zeppelinos.org/gas-station-network-alliance/
https://github.com/tabookey/tabookey-gasless