Oh, math and its challenges. If you’re like the majority of people, chances are you’re not very good with percentages, at least not with the complex ones – fast, if a shirt costs $20 after a 20% discount, what was its original price? This app helps you in those situations where you need to calculate such things without headaches. And the response to my previous question is $25, that was the original price of the shirt.

Percentage Calculator quickly and easily helps you in finding the answer to anything percentage-related. Its dead-simple interface makes it easy enough to use on a smartphone when you want an answer fast (i.e. trying to calculate a tip). To see it in action watch the quick video tutorial below:

httpv://www.youtube.com/watch?v=hS-EsmZ4RQY

The app is actually ported onto Android from a popular same-named web application available at http://percentagecalculator.info

The Android app includes multiple percentage calculations, such as these operations:

  • Simple percentages (i.e. 5 percent of 100 is 5)
  • Percentage increase/decrease (5 percent decrease from 100 is 95)
  • Calculating the amount of tip you have to leave
  • Finding out discount rates
  • Calculating profit margin
  • Converting fractions to percentages (1/5 is the same as 20%)

Percentage calculator is convenient to use (math in your pocket) and useful in many real-life situations. Math doesn’t know language barriers, but in this case the app is translated in 8 different languages.

For more info about Percentage calculator visit http://percentagecalculator.info/about and download it from Google’s Play: Percentage Calculator

Matt, the developer behind Percentage Calculator, agreed to answer to some questions for our readers, so go ahead and dive into the valuable information that he shared with us. Thank you Matt and best of wishes for your little girl!

Q: Can you share some information about yourself with our readers?

A: My name is Matt, I live in Krakow, Poland, together with my wife Kate and our daughter Hania, who’s just had her first birthday. I’m a freelance web developer with a firm a strong belief in spending most of my time working on my own projects. Percentage Calculator is one of them.

Q: I know that you had the web application first, and after that decided to create the mobile versions. How did you come with the idea in the first place, that of creating a percentage calculator web app, what inspired you (friends complaining about how tough it is to calculate the tip :) )?

A: I’m quick with numbers and my friends often ask me simple mathematical questions. Percentage based problems are quite common and I thought there must be good web apps that do it. I spent a while googling and looking at what the web had to offer. “Come on, I can do much better than that”, I though. And I did :-). The original version of the web app only had the “advanced” mode (what you see on the front page), I added other calculators later on, when my office friends suggested that I should make it easier to use.

Q: How long did it take from that first idea until the first public release of the web application? How long did it take to create the mobile version of it?

A: If I recall correctly, it took me 3 weeks to develop the first release of the web app. Then it was polished over and over again. The mobile app uses exactly the same code for the calculator “widget”, but I did a complete rewrite for it. It also took a few weeks for the initial release. And, again, polishing and adding translations (the app is fully translated to 14 languages, I’m working on adding Hindi now) took much more time. I spent most of the last year working on both.

Q: Have you developed other apps or is this your first one? Do they target only the Android market or others as well (i.e. iOS)?

A: This is my first mobile project.

Q: With hundred of thousand of apps in the appstore, how do you make people aware of your apps? I know that the web app helps to send traffic towards the mobile version, but do you do anything different to promote the mobile app alone?

A: Google Play does not give us developers much information on what our sources of traffic are, so I don’t know.

I’m not that good with marketing and I really prefer working on making my apps better. I only asked for reviews on a few Android blogs. Right now I’m getting approximately 900 new users every day, with 800 of them coming from Google Play Store. I also listed it on Samsung’s and Amazon’s app stores. This number keeps growing (yesterday another record was broken – 851 new installs on Google Play). Right from the start I relied on the search traffic. If my friends need help with percentages, so do other people. So my strategy is to rank high and rank in many languages. I put a lot of effort into polishing the app and people appreciate it – I have an average rating of 4.63. Also, all my translations are done by native speakers, which is a big help, too. I just can’t understand why some other devs use translations made by Google Translate – they are simply asking for bad comments.

Q: What future plans you have for your app (new features, variants)?

A: I don’t plan any major new features. I’ve been asked to add a language switcher (right now I’m using whatever language is set for the phone itself, if that language is supported) and to provide a paid, ad-free version. Also, I’ll keep adding new languages.

Q: What popular apps are an inspiration for you as a developer and why?

A: Honestly, I don’t get very excited about “exciting” apps. They’re fun to check out for a minute or two and talk about with friends. What I do get excited about is usefulness. And most of the apps we use on on a regular basis are not flashy – they rely on simple, easy to use interfaces.

Q: Have any tips/advices for other developers that want to start working on an app? Any tools that you consider to be a must?

A: Show your app to your friends. Tell them what it does, just don’t say how to use it. Observe and talk to them afterwards. Real human feedback is by far the best tool.