The point is that the community asked multiple times and they only started allowing apk downloads so people would stop asking. The signal project is open source for auditing purposes only, they have voiced their lament of forks and threatened to ban/block anyone not using an official client and refuse to make it easy to install through a package manager of the user’s choosing. The version without Google cloud messaging has unreliable message delivery, even though there is unifiedpush as a standard that would allow people to register with any push notification service.