nn-search is a simple application for searching words and expressions in texts. Why would somebody need another search tool? Well, most people probably wouldn't, but there are some cases where this application can be useful.

nn-search does not only search words, it can find a word using its part-of-speech tag. For example, it can find a chain of tags like "DT NN VB" that may correspond to such sentences as "a tree grows" or "the dog barks". It can also search words within a certain range, "magic flowers{5}". You can search POS-tags within a range as well, you can make combinations of tags, words and ranges, isn't it cool? The general idea can be seen on these screenshots.

Read more on the wiki.