If you have an old Mac at your home or work that isn't being used, you might want to consider putting macOS Server on it. Even if you don't need hardly any of the features (file sharing, time machine backups, etc), I would recommend running the Caching Server portion of it. Caching speeds up downloads of software distributed by Apple (App Store, iOS updates, etc).

If you have multiple iOS devices in your family, you wouldn't have to download every iOS update or every app update. Once a user on the network downloads it once, it will be cached for other users to download from the local server rather than over the internet. If you have a slower ISP connection, this could speed up downloads quite a bit!

Download macOS Server on the Mac App Store for $19.99