There is also https://www.flipt.io/ https://www.flipt.io/ which is open source. I'm currently building https://flaggy.dev/ https://flaggy.dev/ to be simple and

There is also https://www.flipt.io/ https://www.flipt.io/ which is open source. I'm currently building https://flaggy.dev/ https://flaggy.dev/ to be simple and aiming the best user experience, but initially it will not be open source.