Android 4.3 finally allows 3rd party SMS apps to handle Quick Responses
inline voicemail handling to GV, we aren't holding our breath on this one.Now, as long as an app is updated to handle the option, you can choose your own SMS app to handle Quick Responses. Of course, the key phrase there is "as long as an app is updated..." As yet, we haven't seen any of the more popular SMS apps like Handcent, Chomp, and Go SMS updated to take advantage of the feature. And, even Google's own Voice app hasn't yet been updated, although given how long it took for Google to add
We'll keep an eye out though, and let you know when apps are updated to be able to handle Quick Responses.
source: Android Central