Приложения разработчика Peter Gottlieb в Android Market

multtables (v. 5.0)

Peter Gottlieb опубликовал приложение 2012-11-17
(обновлено 2012-11-17)

Here is the answer to those tiresome multiplication table exercises with your child.  This Android app will flash a sequence of multiplication table questions, and you child will enter the answers to each using a virtual numeric keypad with nice large keys.  The virtual keypad even has a “delete” key so that hitting the wrong button can be corrected before getting charged with a wrong answer.   Each question will be selected randomly by the program.  You (or your child) can select the total number of questions for the sequence before the start.  Since a given sequence will have no repeated questions, there can be up to 28 different questions in the sequence.  Another unique feature that distinguishes this app from the countless other flash-card type apps: after each incorrect answer the subject is forced to view the multiplication table so that he/she is forced to become familiar with the table and its relationships.  

The number of correct and incorrect answers is tallied and displayed at the end of the session so that you can verify your child’s progress.  In constructing the multiplication table questions the numbers 10 and 2 are omitted because they make the multiplication question too easy, and the child would be annoyed at having to waste time answering trivial questions.

myformulas (v. 5)

Peter Gottlieb опубликовал приложение 2012-08-13
(обновлено 2012-08-13)

This app is for anyone who has to calculate formulas: high school and college students in science, engineering, or business courses, as well as teachers or practitioners in any of these fields who need to get quick results when they are not near their computer. It will handle a wider variety of formulas than most hand-held calculators, particularly formulas for which you want to use named variables and change their values frequently.  Not only is this app easier to use than most hand-held calculators (being able to use parentheses rather than the tricky reverse Polish format required by most HP machines), it is also easier to use than the formula editing feature of a spreadsheet.   Entering formulas is a snap: all you have to  do is type in characters as you would with a text editor; the program parser will identify any variables and set up a screen for you to enter their values.   Alphabetic and numeric characters are entered on different keypads in order to provide you with larger keys to minimize data  entry errors.  Close integration makes switching between these keypads very fast and easy.  

Once you have entered a  formula structure, and the initial values for any variables it might have, you can name and store it for future use.  You can scroll through the list of stored formulas and recognize by name or formula structure any that you want to re-use.  

Business or financial users will find this app a good complement to the calc_formulas app (by the same author and available for free), which allows the user to select from a list of 27 frequently used financial formulas, but does not have the capability to create new formulas.  

The only deficiency in “myformulas” is the absence of a built-in function library.  If more than 1000 people will pay $2.50 for this version, I will produce a slightly more expensive version with a function library more complete than any spreadsheet.

calc_formulas (v. 3)

Peter Gottlieb опубликовал приложение 2012-01-08
(обновлено 2012-01-08)

Here is an app that can calculate 27 different formulas useful in financial transactions.  This latest version of the app has added a numeric keypad (with nice large keys) for data entry, as an alternative to the 2 modes of data entry in the original version: (1) dragging your finger up or down the screen to increase or decrease the default value of an input parameter, (2) tapping on a blank space on the screen for the same purpose.  
The 27 formulas can be divided into 5 categories: (1) interest functions which range from simple interest to mortgage payments to bond price to yield a specified interest when the stated rate of the bond (frequently called coupon rate) is specified, (2) notes and payments, (3) profit and loss (including internal rate of return), (4) inventory valuation, (5) depreciation.

This app can only calculate the 27 specified formulas, but it is free.  If several thousand people download it and give me favorable reviews, I will do an enhanced app (for which I will charge a few dollars) that will allow the user to specify his/her own formulas, which may incorporate one or more of these 27 hard coded formulas.

quickview (v. 1.0)

Peter Gottlieb опубликовал приложение 2011-12-14
(обновлено 2011-12-14)

Can you read a number that's flashed on the screen for only a few milliseconds? This game will start with a few hundred milliseconds and reduce the duration until you can no longer enter the number correctly.  You can select the number of digits; 3 is very easy; 5 is very hard.  Practice and notice the improvement.  Find the time of day when our visual acuity and ability to concentrate is highest.  Test your skill against friends and family; it will be rewarding activity for ages 8 and up.   This initial version is free, but not very slick;  if it generates sufficient interest, I will add many features (such as keeping statistics on scores and for different players) and charge a few dollars.