Hermes is the only quick reply tweak that supports Messages, Kik, and WhatsApp. Not only can you quickly reply to text messages, you can also quick reply to Kik and WhatsApp messages as well.
Hermes gives you the power of quick reply to your favorite messaging apps without the unnecessary bulk of other quick reply tweaks. Hermes was built to be as lightweight as possible, meaning it has virtually no impact on battery and is as efficient as possible. Unlike other tweaks, Hermes uses iOS’s existing alert system meaning no resources and no battery life is wasted.
Hermes is open source. You can check out the code here.
You can purchase Hermes from the Cydia Store for $0.99. If you don't already have Cydia on your device, you can find instructions on how to jailbreak via the iClarified Jailbreak Wizard.