Callback for Messages is a tweak available from the past days in Cydia for iPhone, iPad and iPod Touches running the operating system iOS 8, implementing a speed dial button.
In the image on the left you can see exactly what it is about, the tweak displaying in the LockScreen a call button next to the notifications for the messages of the Messages application, it being displayed next to the message for quick response.
Callback for Messages allows you to quickly call back a contact straight from the Message notification. To use, simply swipe the notification — either in the Lockscreen or Notification center — and select Call. That's it! No passcode, no muss, no fuss. Just a quick callback!
Callback for Messages also has a settings menu in the Settings application, Configurations, of the operating system that allows you to control how its functionality is implemented, but also how the call button looks.
Callback for Messages is available for download from Cydia's ModMyi repo.
