You can block or unblock a number on an Android phone using the built-in Phone app's "Blocked numbers" menu.

To unlock a Boost Mobile phone, you'll need to call the Boost Mobile Customer Care line at 1-888-266-7848 and request it.

There are plenty of good reasons to block someone on your iPhone. Maybe your ex broke your heart but still rings you when bored. Or perhaps you’re tired of the supposed friend who sends you memes at ...