After going through this tutorial, you must have gained good understanding of debugging a C or C++ program using GNU Debugger. Now for you it is very easy to learn other debugger's functionality because they are very similar to GDB. It is highly recommended to go through other debuggers to become familiar with them.
There are other good debuggers available:
DBX Debugger: This debugger ships along with Sun Solaris and you can get complete information about this debugger using man page of dbx ie man dbx.
DDD Debugger: This is a graphical version of dbx and freely available on Linux. To have a complete detail, use man page of ddd ie man ddd
You can get comprehensive detail about GNU Debugger from the following link