Not sure, but NOVA 3 is 1.69GB. So on the surface it would appear that you have enough. But in order to unpack/unzip the app, it needs additional space temporarily for the "zipped" app and the "unzipped" app. Then after the install is finished, the "zipped" version is removed. So I would guess that the total of the zipped and unzipped versions is more than the 3.2GB you have available.