Why do you have to install additional software so you can expand memory with a pen drive on the nexus 7?

Someone I know has a lenovo tablet and it needs no additional software apart from a file manager app.

It's to force you to use Google's cloud based stuff.

It is one of the few bad things about the Nexus, but to be honest the internal memory is big enough for most things I do and there are ways around things.

Yes it's because Google's vision is of the cloud.

If you don't share that vision then you have choices.

It doesn't force you. It just nudges you in that direction. There are plenty of alternatives if you don't want to use Google's cloud services. With my Nexus 7 most of the content gets streamed from my NAS box. In all the time I've had it I've never felt the need to connect a USB drive to it

How do you stream from your NAS to your Nexus - which software do you use?

I can't speak for LostFool but most Android File Managers will pick up NAS drives pretty easily. Alternatively, if your NAS drive supports DLNA/UPnP sharing (most WD devices do, for instance), you can use an app such as Bubble UPnP.

Both options work really well within a home environment, although this isn't really an 'on-the-road' solution.

I have a Synology NAS as a media server and use Bubble uNnP on my Nexus 7 (and Nexus 4)- it's a fantastic piece of software and I can even use it to control the WD streaming box connected to my TV.