Text people from your Mac, even if they use Android

One of the greatest functions of iMessage is that you can easily text from a device other than your iPhone. It's great to be able to type on a regular keyboard. But unless you go through some extra steps, you can only text other Apple users from your Mac. It also allows you to receive text messages from services such as two-factor authentication. If you use Safari, this means that Safari can autofill these codes for you.

First, make sure you have iMessage fully configured.

1. On your iPhone go to Settings > Apps > Messages. If you are offered to sign in to your Apple Account go ahead and do so. Make sure that the iMessage switch is "on".
2. Tap "Send and Receive". The first group is the numbers and email addresses that people can reach you on. Feel free to turn all of these on. This doesn't connect to your email account, it's simply that if someone tries sending an iMessage to one of those email addresses it will come through to your Message app. In other words, there are no actual email messages involved, they are just used to identify who you are.
3. From the second group choose one address, which will be the source, or "caller ID" on your outgoing messages. For most people, I recommend choosing your phone number.
4. If you have any iPads, go through steps 1 to 3 on each of these as well. Step 3 is the key.
5. On any Macs you want to get texts we go through a similar process. But instead, you will open the Messages app (in your Applications folder or use Spotlight or Siri to launch it).
6. Click the Messages menu > Settings. Switch to the "iMessage" tab.
7. Sign in if needed.
8. In the first group "You can be reached for messages at", I recommend selecting all the options. At the very least select your phone number.
9. Below that, under "Start new conversations from" choose your phone number

Now that iMessage is configured across your devices you can connect regular text messaging to message people on Android.

On your iPhone go to Settings > Apps > Messages > Text Message Forwarding, and slide the switch on for any device you want to enable for plain text messages

Troubleshooting

• If you are stuck on "waiting for activation": Try signing out of iMessage on ALL of your devices. Reboot all of your devices. Sign in on your iPhone and wait. You do not need to stay on this screen while you wait. Go do something else and come back. It normally takes only seconds but when Apple's servers are overloaded (such as on an iPhone launch day) it can take hours.
• Why am I getting all of these pop-up notices that iMessage has been enabled on a new device? Apple just wants to be sure that if someone stole your password you are alerted. Otherwise, they could be intercepting your text messages. Since you know this is you, just tap "OK".