How to send a text message to someone who called me using Android 5.1 It seems to me like there should be a way to send a text message to someone who called without having to save that number in the contacts list, but I can't figure out how.
I'm using pure android 5.1.1 with default apps.
Updated Answer, for Android 6:


On the Phone app, go to the tab with the clock icon (the middle tab).
Tap the number that called you.
On the drop down menu that opened below, tap Send a message.


Original answer, for Android 5.1:


On the Phone app, go the RECENTS tab.
Tap the number that called you.
On the drop down menu that opened below, tap DETAILS.
Tap the three-dots-icon on the upper right of the action bar, and choose Edit number before call.
Tap the three-dots-icon to the right of the number, and choose Send SMS.