The Tennis Ladder Administrator is a Java application which automates a lot of the tedious work you would normally have to do with pencil and paper in order to be the administrator of a tennis ladder.
Here's the score entry app
The roster app
Project Admins:
I stopped maintaining and enhancing this project years ago, but seeing as how I received an inquiry recently I loaded all the files into an Eclipse project which is now available as TennisLadderAdmin.zip
The automated emailing code has become outdated and no longer works, that would need to be fixed if anyone wants to use it.
While this program is considerably more convenient than trying to run a tennis ladder with pencil and paper, it is still a lot of tedious work.
The downside of this system is that you have to collect up all the scores (probably via dozens of emails) and enter them manually into the program yourself. That can be very time-consuming if the ladder is large. Then you have to manually click buttons to move the players up and down appropriately for each new round which is also a chore (though that could probably be automated in the code, I did not implement that level of automation).
You might want to consider a browser-based solution instead of this. Ideally the players would at least be able to go to a web page and post their match scores themselves. Also the new match assignments could appear on a web page.