And you're even able to assign policies based on a time range, so for example an office might have a very loose policy at lunchtime, but something much more restrictive for the rest of the day. These policies can be applied to individual network users, or groups of users.

If you need more control, it's possible to create NxFilter policies which block sites by category (75 in total), or only allow access to particular site categories - or all internet access - for a certain amount of time a day. A browser-based console displays stats on web traffic, blocked domains and more, as well as logging every site you've accessed. Get NxFilter running on one PC, though, and it brings benefits right away, blocking known phishing sites and using packet inspection to detect some malware.

It's still not difficult - if you know how to configure your system to use a custom DNS server then you won't have much trouble - but you will have a little work to do. NxFilter isn't for network beginners, it won't fully set up everything itself, and even the web tutorial doesn't walk you through every detail.

You'll first need to install and configure the program, of course, and that can take a little effort. It's also possible to limit access by user and time, and one NxFilter installation can protect your entire network. NxFilter is a powerful Java-based web filter which controls access to web sites based on their domain names.

For iphone download NxFilter 4.6.7.4