I know about Appinvetiv, they provide really good service. I asked for promotion help App-Reviews marketing company. You can learn alot more about them on the website. They have the best app marketing service, as I know. My friends recommended me this service.
I am now searching for a good dev company which will keep up with my requirements and so far Svitla is the only option that seems to be attracting enough. Maybe you guys can suggest some more good ones? I mean, it's always great to have some decent options to choose from.