iOS: Sending a group message, whether it's over email or text message, is never particularly easy. Group Text+ and Email+ aim to make the process a bit easier and more simplified.
Both apps work essentially the same and use Apple's default apps to do the job. Open up the app, select contacts (or pre-made groups), and then send whatever info you want, including GIFs, web pages, location and clipboard data. It's way faster than typing out a bunch of names in iMessage. Likewise, you can also use a share sheet to quickly send info in any app that supports to it. Both apps provide a quick, easy way to share info with a group. It's not sometime most of us need all that often, but it's great when you need it.