TeleQuery's TQ Plain Text File Search app is an elegantly simple plain text, up-to-three term search tool.
Any plain text file with a CR or CRLF at the end of each line (record or row) will do; no other formatting is required.
I designed this app so I could keep track of a file of contacts, appointments, logins, passwords, license keys, and any other plain text content. If you just name it with a ".CSV" extension (it doesn't have to be comma-separated content, but it can be), you can fool a browser into reading it in from a server or other machine somewhere and save it in your Android Downloads folder (a.k.a directory). Or, you can just connect your USB cable between your Android and your computer, then place the plain text file on the Android wherever you want it to be found when you start up the app and you're prompted to "Click to load file!"
Once the file is loaded into the app, every time you re-open the app, that file will be automatically re-loaded. Of course, you can change it whenever you want. And, you can even add a second file, so that searches can apply to both files.
A main functional objective was to be able to press any NNN-NNN-NNNN-formatted telephone number and automatically have it entered into the phone app for calling. And, if you have a voice-to-text-capable keyboard, you can just speak the search terms into the search line. It's awesome, if I must say so myself.
So, the process is: load a file (or two), enter a first search term, and optionally, a second and third, press "Search" and have the match(es) appear instantly.
If you're familiar with Linux or Unix, this search is like running up to three successive grep commands: the first on the entire file of thousands of records; the second on the result of that search; and the third on the second's output, thus narrowing down the final result to a manageable number of records. All three are not required; just one or more.
For example, in Linux, the command line would look like this :
grep "radio" filename.csv | grep "shack" | grep "dallas"
20120905-09 radioshack dallas 214-566-0224,1601 northwest highway dallas tx,,,,,,,,,,,,,,,,,,
I have a rule: each matching record must be displayed in its entirety. You'll see how we've done it. Again, I hate to brag, but it's awesome.