This is the fourth blog about Blindfold Pool.  Click Blindfold Pool for earlier blogs about the game.

When you play against a computer player, you want a fair game.  The computer opponent can’t be too much better or worse than you, or the game isn’t fun.

The computer opponent in Blindfold Pool works like the computer player in Blindfold Bowling.  Based on the skill level you pick, the computer picks a clear shot, and then may or may not make the shot, based on a simple mathematical formula.  The further the shot is, the less likely the computer will make the shot.

If the shot is easy, but the mathematical formula determines the shot was a failure, the computer shoots either too powerfully, or the angle is slightly off.  That too is part of the mathematical formula.

If there’s no clear shot, the computer just shoots into the pack of pool balls, hoping for the best.

As you play the game, you hear the computer announce what his intention is, you hear the shot, the balls knocking into each other, and finally, the result.

Like the other Blindfold games, you can change the name and voice of your opponents, in addition to its skill.  Some of the games even let you set the type of player, such as aggressive or passive, or better at certain types of shots.

The mathematics behind the combined skill and luck factor is pretty easy, but I won’t go into here.  Click to read my other blog about building computer opponents.

You can download the game here: https://itunes.apple.com/us/app/blindfold-pool/id1099269929?mt=8

When I was watching the July 4 fireworks a few months ago, I closed my eyes for a little while to try to appreciate only the sounds, not the visual effects.  The audio environment was as rich as the visual environment, and I thought I should make a game like that.

My first idea was to create a fireworks game, where each time you tap on the screen, a different fireworks sound is played.  I suggested this idea to the group of visually impaired game testers, and several of them said they would prefer to use that sound to make a audio greeting card, and send the audio e-card for someone’s birthday.  Thus was borne Blindfold Greeting Card.

I envisioned the app to appeal to several groups.  For the blindness community, it would let them send an audio e-card to someone, and let the recipient appreciate the card the same way as the blind person who created it.  For relatives and friends of visually impaired people, it would let a sighted person customize an audio e-card that is not burdened with a visual description.

When a blind person receives an e-card with a picture, he hears what you wrote in the e-card, and a description of the picture, such as “cute dog in the middle of a grassy field”.  It doesn’t have any of the emotion or impact of what the picture might engender.

With Blindfold Greeting Card, you first pick a sound effect from 20 categories (about 400 sound effects in total), such as fireworks, marching drums, car horn or crackling wood fire.  Then you record your greeting by speaking into the phone.

Blindfold Greeting card merges the sound effect with your greeting, and then lets you send it via email or as a text message.  You can also post it to Facebook, Twitter or any other social network.  Here are examples by three of our testers:

The app is slowing catching on.  It seems like every time someone receives an audio e-card,  they download Blindfold Greeting Card and start sending audio e-cards to their friends and relatives.

Blindfold Bird Songs was such a popular matching game that I started getting requests to do a similar game but with animal sounds.

Just like Bird Sounds, Sound Search has two modes: Name That Sound, and Find That Sound.  The first sound pack I created was common animals, such as chickens, dogs, baboons and elephants.

Name That Sound presents two columns: the left column is a sound name, and the right column is the sound.  First you pick an name in the left column, such as “gorilla”, and then you pick a sound from the right column.  If it’s a match, you win 3 points, and the gorilla is removed from both columns.  If it’s not a match, you lose a point.  Level 1 in the game starts with 3 animals to match, and continues through level 25, adding 2 more animals on each level.

Find That Sound starts out with 6 animal sounds, 2 rows of 3 items.  Similar to the memory game concentration, you have to find the match.  For example, the first row would have gorilla, bear and gorilla, and the second row would have dog, bear, dog.  To match the gorilla in the upper left corner, you would have to pick the gorilla in the upper right corner.  Level 1 starts out with 3 animals to match, and continues through level 25, adding 2 more animals each time.

Once the game was working, the testers suggested adding more animal sound packs, so I created a Fun Common Animal pack, where some of the animals given different sounds (such as different dog barks).  The Animals of Asia sound pack includes camels, orangutans, dingos, leopards and dozens of other exotic animals.

I released the app, and was immediately deluged with more sound pack requests.  I added an Everyday Sound Pack, including sounds like a toaster popping or a garage door opening, A National Anthem Sound Pack, with anthems from dozens of countries, and a Musical Instrument Sound Pack, ranging from a piano to a tabla to a singing-saw.

If you have ideas for more sound packs, let me know.  You download the game at: Blindfold Sound Search.