A golf handicap enables you to gauge the quality of your game and compare it to others, regardless of what course you play. As part of the Rules of Golf, the USGA has created an algorithm for calculating your handicap based on your most recent 20 games.
With the Golf Handicap Calculator from earth42, you can enter rating and slope parameters of golf courses you play, and then enter your score and course for each game. Once you have at least 5 games stored, it will calculate and graph your "differentials", the normalized scores, and your "handicap index"; and once you have a handicap index, the calculator can also predict your score for a stored course, or from a rating and slope that you enter.
NEW with version 3: You can now enter a nine-hole course handicap and use it to record a nine-hole round. The app will normalise both kinds of scores together as needed, and present your handicap index as either 18 or 9 hole depending on your preference.
The data you enter for this app is held only in your device, in a protected area. You need no network connection for it to work. The only reason it requires a network connection is to show a small banner ad on its main page.