This calculator is available on the Android Market with the description 'Standard Calculator' and the name 'StdCalc'. The calculator is a standard arithmetical calculator designed to be more functional than the default installed model - it also includes a tip calculator and a loan calculator, both of which can be accessed from the menu - features of the main calculator include:

• decimal mode
• fractions mode
• the full text of the calculation is displayed as it is entered
• the output text can be set to scroll either horizontally (the default) or vertically
• the full text of each calculation is stored in the history
• results of each calculation can be reclaimed from the history and reused in future calculations
• the settings layout includes a range of colour schemes to suit different moods
• the option to move to the SD card for 2.2+ users is also included

The colour scheme of the calculator (Figures 1~6) can be changed in the 'Settings' tab in the menu (Figures 7~8) via 'Button Colour Selection' - the default colour scheme is Blue. Other options available via the 'Settings' tab in the menu include choosing the maximum decimal places (default is 4) and the maximum number of records to be stored in the calculation history (default is 10 records), plus whether to enable vibration mode for the calculator keys (default in On) and whether to convert the calculator to fractions mode rather than decimals mode (default is decimals mode).

A detailed help facility is available (Figure 9).

Once a calculation is completed, the full text is automatically stored in the calculation history (Figures 10~11) which can be viewed via the 'History' tab in the menu. The maximum number of records that can be stored can be chosen in the 'Settings' tab - up to 100 records can be stored - the default is 10 records - once the maximum has been reached, the newest entry will overwrite the oldest entry - the number of records that are currently stored (and the percentage of storage vs. the chosen maximum setting) is displayed together with the history. The input to the history is prefixed to show which category of numbers was used to perform the calculation i.e. 'DEC' or 'FRA' to represent either decimals or fractions. The results of the calculations stored in the history can be input into a calculation by short pressing on the relevant calculation text - the value will be converted according to the mode that the calculator is in when the history is accessed - for example, a fraction would be converted to decimals when not in fractions mode and a decimal would be converted to a fraction if in fractions mode. Very large or very small numbers (i.e. those raised to a power) are not available for insertion into a fraction. History records can be deleted individually by long pressing on a record in the list - alternatively, all the records in the history can be deleted by pressing the 'Delete History' button. The history can also copied to the clipboard if needed (note that an html-based text editor/viewer is needed to subsequently display the clipboard data properly).

In fractions mode, each fraction is entered as a sequence separated by a decimal point (which will be shown on the screen as a comma) in the format whole number, numerator, denominator - once an operator is pressed, the sequence is converted to a fraction - if the fraction value is less than 1, it is only necessary to enter the fraction numerator and fraction denominator separated by a decimal point and then press an operator - the next fraction is then entered using the same sequence followed by an operator - this is repeated until the equals operator is pressed when the whole text of the calculation, with its result, is shown in fraction format (Figures 12~15).

The tip calculator is shown in Figure 16. Following the instructions given on the screen, the buttons are used to input the bill amount, the target tip percentage and the number of people who will split the bill. There are two options available via the Settings tab. The first option, Payment Rounding, when checked (the default), allows that, in the case where the bill cannot be split exactly between all of the people sharing the bill, all of the people except one will pay a whole number (no cents) whereas the remaining person will pay a slightly higher number (including cents, if appropriate) to make up the balance. In the second option, Tip Rounding, there are 4 modes to choose from: 1) No Rounding (the default), 2) To Multiples of 1.00 - the tip is rounded up to the nearest whole number, 3) To Multiples of 5.00 - the tip is rounded to the nearest 5 whole number - i.e. if 5 or over will round up to 10, whereas if under 5 will round up to 5 - i.e 7 will round up to 10, whereas 4 will round up to 5, 4) To Multiples of 10.00 - the tip is rounded to the nearest 10 whole number - i.e. if 5 or over will round up to 10, whereas if under 5 will round down to the next nearest multiple of 10 - i.e. 15 will round up to 20, whereas 14 will round down to 10. The status of each of the options chosen is shown on the Tip Calculator screen

The loan calculator is shown in Figure 17. Following the instructions given on the screen, the buttons are used to input the loan amount, the annual interest rate and the term of the loan in years following which the monthly payment required to pay off the loan will be displayed together with the total interest to be paid and the total amount that will be repaid.