Default [Q] 3rd Party App to send SMS through Google Voice?

I have a major performance issue sending SMS through the Google Voice app - sometimes it takes 15 minutes to deliver a text, even over wifi - which makes no sense considering we are talking about the transfer of maybe 100 bytes of data. I only use this so the texts I send come from my GV number rather than my carrier number. Is there any other app that can achieve the same thing? Or some other workaround other than waiting for Android L and hoping it is finally fixed there? I have a rooted phone but cannot load a custom ROM. I know CM has some nice GV integration in it - but not an option with my locked bootloader.