Just a little tidbit you may find useful... GV Mobile dev released GV Mobile on jailbroken iPhones for free after Apple removed it. Also, GV Mobile+ is now out for jailbroken phones with a few extra features.
Also, if you're looking for a way to get Google Voice SMS pushed to your phone, you can do what I'm doing! Download the Free or Paid version of TextNow. You can set that up with a custom email address like
myName@textnow.me. Then on Google Voice you add that to your email addresses. It'll text you a confirmation with a link you can't click. Copy the entire message and paste it into notes so you can clip out the portion with the link. So now copy the link and then paste it into Safari and go there and you'll confirm the new email address. Now you can go into Google Voice settings and set your SMS Forwarding to your TextNow email address and turn off forwarding to your mobile phone. It works perfectly. They look just like text messages and push right to your phone. You get badges and all. The only downside is you can't send initial messages to others using your Google Voice number. So you have to use the Web App to start your convo but then after that you'll be able to respond easily with TextNow.
Hope that helps for now until Apple decides to suck it up and let GV into the app store again, or until we all decide to surrender to Google.