Is it possible to develop an iOS app without a test device? So...I have an iPad and MacBook Pro. 

I bought my iPad because I thought I needed it but now I'm thinking to sell it since I just found out that Xcode offers an iOS simulator. 

Is it possible to develop a fully working iOS app without actual test hardware?
Clearly: No. The simulator does not offer hardware access (gyroscope, accelerometer, etc.) and also, you just don't get the feeling for your App, which is very important in iOS development. You can't use the gestures and you don't know how it reacts if you work with it. so it is definitely not advisable. I tried to use the simulator in the beginning, but some frameworks don't even run on it.