Spotify on a G-3 I phone
 

Are they compatible or do I need to get a G-4

Are you talking about an iPhone 3G?
If so, do yourself a favor and go buy a new phone.

Most likely referring to the LG line of smartphone.

I don't see why it wouldn't be compatible with a G3. Did you download it from the Google play store?? Aka, app store?? If so, connected to wifi? Created a user account??

gtc, yes I have an iPhone g-3, a hand me down from my son, he gets a new model and I get his old one
JD159 used the app. store and it says I have top load the ios-7 but I haven't been able to do so any hints or just go get an upgrade phone?

In that case, I don't think Spotify will work on that phone.

The 3g will not be able to update to an operating system new enough to be compatible with Spotify. Your out of luck!