Q:

what is the most professional way to make an android app

I am creating an app (not a game), and I want to make it look professional. I have two options right now of how to make it. The first one, goes straight into my app and then has a menu when you hit the menu button on the phone. The second is, that when you open the app, it goes into a “main menu” like the kind that you would find in a game, where there are options such as “start”, “help”, “settings”, and “exit”. The first option seems more professional, but I am worried that it will cause the app to look like it has less “substance” to it. Which one should I choose? If I choose the first one, will it effect the amount of customers that will buy or return my app? Is there a third/better option for the UI of an app?

A:

I would go for a "main menu" if you can only choose one of the two options. Otherwise, like you said, it will look like there's not much substance to the app. The fact is that many of my Market customers have seen the lack of a "main menu" as a lack of functionality. 
The best bet is probably to use both: have a main menu, as well as an actual menu driven by the device's menu button. This is the approach I use for my apps in the Market.

