Downloading nlock 1.0 from our website was free. The program lies within Games, more precisely Puzzle. NLOCK.EXE is the default file name to indicate this program's installer. This free program is a product of Ihsan. The following version: 1.0 was the most frequently downloaded one by the program users.
From the developer:
Break the lock combination and make four numbers from a set of eight numbers and four plus and minus. Given numbers are on two circles, four horizontal and four vertical, and signs are on one circle in the middle. A pair of numbers and a plus/minus sign are aligned forming an equation and a resulting number.
You may want to check out more software, such as Kana Attacks!, States' Liberty Quiz or Dotty & Letty, which might be related to nlock.