CheckMail

checkmail is a powerful pop3 email checking program.
ZeroIn

Change between long filename directories with ease

check your hard disks for errors and correct them. easy to use, fast and free.
Check Mail (GMail)

Lightweight customisable new mail notification utility for Gmail accounts.
VerCheck

vercheck checks websites for new versions of the software you use.
MimeCheck

check that a server is sending the correct mime type for any given url.
InWords

Java code to converts number to words in any of 24 languagues.

CheckDisk is a powerful tool for searching and repairing disk errors