What other intermoelcular forces can exist between neutral molecules?
This can be a bit tricky when you are first starting your journey into the world of intermolecular forces. What I like to look for first are what (if any) heteroatoms are present when the backbone of the molecule is composed of carbon atoms. 

In your case there is a nitrogen present and it is attached to 2 hydrogen atoms. This is a perfect example of a molecule that will exhibit hydrogen bonding as an intermolecular force. Hydrogen bonding, at least in my opinion, is the easiest to pick out. N, O, and F atoms bonded to Hydrogen are the only species in which this attractive force between molecules is observed. Now if you were to remove that $\ce{NH2}$ group and just had $\ce{CH3CH3}$ you would be correct. The only intermolecular force between the molecules would be London forces.