https://releasehub.com/ (Disclaimer, first listed because I work here)

https://www.quali.com/

https://www.withcoherence.com/

https://webapp.io/

https://www.uffizzi.com/

https://www.qovery.com/

https://www.devzero.io/

These exist in the B2B space (and isn't an exhaustive list), there are a ton more in the B2C space