App: Xmart Calculator Pro - Desktop
Developer: XHLIU
Genres: Productivity, Finance

Let's look at some simple questions: 

Question 1: 
James can make $200 per day, what would be his annual income ( He works 5 days a week, 48 weeks per year) ?

This is easy, just enter an expression as this in Xmart Calculator:  200 x 5 x 48

Question 2: 
How many times of tapping a button to calculate his annual income?

8 times on a normal calculator, 7 times on Xmart Calculator (you don't need to tap the '=' button).

Question 3: 
What if his day rate is $320, $400, $500...?

Well, very similar: 
320 x 5 x 48;
400 x 5 x 48;
500 x 5 x 48...

What's the problem? With a normal calculator, we have to enter the same buttons 'x 5 x 48' very time when the only value changes is just the day rate. 

Is there any way to just enter the day rate  and the result will update automatically?

With Xmart Calculator, YES! You can define a Algebra function like this:
 
"IncomeByDay(X) = X x 5 x 48" 

Then you can just select the function and enter the value for 'X' and the result will update straight away! 

To get James annual income, you just need to tap buttons 4 times.

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End of questions
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Xmart Calculator is appreciated as an intelligent, programmable and expandable calculator based on text expression. 

In addition to most of the common and scientific functions, users can also define personal functions.  

All calculations are step-by-step traceable.

**Quick start:

* Use the keyboard to quickly enter expressions/formulas 
* When using keyboard, press '*' for multiplication and '/' for division
* Click '=' to save the calculations

**Basic features:

* Instantly calculate and show result, no need to press the '=' button
* Save calculation to history 
* Name/label a history item meaningfully
* Recall history item or expression
* Record and show step by step details of the calculation
* Share history with friends

**Advanced features:

* Turn ON/OFF the button sounds and custom the sound
* Turn ON/OFF automatically saving
* Configure colours and fonts

* Custom functions: user can define any algebra functions with up to 9 parameters.
* Use a custom function in the main expression or play with it separately. 
* Support most scientific math functions.
* Fast mortgage calculator is included

Release notes:
Bug fix for mortgage calculator and auto save settings.