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Author: Andrés

Letting go

Letting go

After more than 7 years maintaining CambiosUY it’s time to say goodbye. It has been a great experience developing this app and getting so much great feedback.

I started developing CambiosUY just to learn how to develop an app for iOS. I wanted to do something simple and useful. In Uruguay we still rely so much on the US dollars for big purchases like cars, houses and even some electronics. The price of the currency goes up and down, so it’s useful to have some way of checking what the price is before you decide to do a purchase like this. We also use other currencies when we travel, for example Argentinian pesos when we travel to our neighbor country or Euros when traveling to Europe.

Basically, the app was divided in 3 sections:

– One where you could choose between 7 currencies and see what was the price for that currency. In this section you could also see the evolution of the currency over the last week, month and year. There was also a recommendation whether it was a good moment to buy or sell the currency. This was based on the current price and whether the value was higher or lower compared to the one over the last weeks, months or year.

– Another section where you could use your current location to see money exchange places to buy or sell foreign currencies.

– And finally, one of the most useful to me, that was a calculator that told you the equivalent value of some currency. For example if you have 40 Uruguayan pesos you could get 1 dollar, and so on.

At some point, I added an in app-purchase feature that sent notifications when a certain currency went above or below a certain threshold. This was useful for people that were waiting for a certain currency to go down so they could buy it at a lower price, or sell it when the price increased.

After a couple of months that I released the app, and with the help of some ads, I managed to turn CambiosUY in the most downloaded app in the iOS store for a few days. This was huge to me, the app was being downloaded more than Facebook, Whatsapp or the most successful apps at the moment.


So, after all this, why letting the app go?

Many reasons, but the main one is that I would like to focus in other things. The apps is no longer being used as much as it used to. I haven’t added any new feature or improved the app in the last few years. Sometimes we carry over with many things that doesn’t help us move forward, so it’s better to just let it go.

It was a great experience, and I would like to write about lessons learned and the technical details of how I implemented the app in the future. But for now it’s time to say goodbye and think in what to do next.

Why I decided to create my own videogame?

Why I decided to create my own videogame?

It was 1996, I was six, and my parents took me and my brother to the Computer shop to get our very first computer. Back then in Uruguay it wasn’t that common to have a PC at home, but it was getting more and more popular. It was the beginning of the Internet as we know it Today and a lot of newspapers and magazines made lists of what kind of things you could do with it; from visiting the Louvre to browsing Disney’s website with pictures and lists of their movies. This for sure would bore any millennial nowadays, but back then just seeing Mickey Mouse in full colors in your screen while it slowly loaded because of your 56k connection, was very exciting.

However, for me, the interactions I had had with computers were very limited. Most of them happened while visiting my mom’s work. She worked in an office, which was full of computers but not necessarily did a lot of things that could excite a kid in the mid 90s. Their main use was text processing and calculations. I remember one of my first times there, I saw in the distance a computer with an animation of Donald duck cleaning a window. I asked my mom: “Can you play with it?” and my mom said: “No, that’s just an animation that shows while the computer is not being used” (needless to say, that was a screensaver), but she added “but you can play with this one. Here, you have these cards that you need to try to group following this order”. Solitaire was actually fun to play, but not something I was impressed at all.

So, coming back to that day in 1996 where we went to the computer shop. My parents entered an office where they talked with the sales person that explained all about the computer. Let’s not forget that buying a computer wasn’t a thing you would do very often. The prices were still quite high and my parents wanted to know all the conditions of that purchase. I found that boring, so me and my brother just waited outside. At some point we just saw some color lights flashing at the end of the corridor. It was probably one of the latest PC models that the shop was selling that was there in display. In it, there was an animation of this green rabbit, running like crazy and shooting turtles. The animation was even more impressing than Donald Duck cleaning windows, so I just thought it was another screensaver. But then a sales person came with some prospect buyers and said to them “Oh and you can also play with it”, hit enter and started to move that rabbit everywhere. The game in question is Jazz Jackrabbit, and to be fair it wasn’t the latest game at the moment with the most advanced graphics. For me, I just couldn’t believe it, videogames were not a new thing to me, I had my Nintendo Famicom at home, but videogames on a computer for some reason just blew my mind.

From that moment, everything related to computers became so interesting to me. I decided to get a degree in Computer Science and work as a Software Engineer. But the walks of life just take you to different places (that are also very exciting), but not very close to videogames. So, recently I just decided to give it a go and try to get closer to this world again. Now with game engines like Unity, getting started to build your own videogame is not hard at all, so that’s what I have been doing in my free time lately.

The videogame I built is called “Perdidos en el Tiempo” and is a platform game (not a coincidence that Jazz Jackrabbit was a platformer as well) where you impersonate a native person in the past that has to help a girl that got lost in time trying to save the world.

It’s a very short game and for somebody that plays videogames nowadays, a very rudimentary one. But I feel proud to have been involved in the process from beginning to end and to learn more about game development. Definitely this is just the beginning, I would like to learn more about it and try different things. Most importantly, to keep getting impressed and excited like that kid 24 years ago.


This is what a PC in 1996 would look like. It was the beginning of multimedia, and Windows 95 was getting extremely popular.

disney-1996Disney Website in 1996. One of the top websites recommended to visit by the newspapers and magazines at that moment.

screensaverScreen savers in the 90s were sometimes more impressive than most of the things you could end up doing with the actual PC.


Solitaire would come for free in Windows 95 and was an addictive way to just kill the time.

jazz-jackrabbitJazz Jackrabbit was a game released in 1994 for DOS. You play as a green rabbit who has to rescue a princess and kill everything that get’s in your way. Reminds me a lot to Sonic the Hedgehog for SEGA.


Unity is one of the most popular game engines at the moment. It’s quite easy to learn and you can build your own game in minutes.

perdidos-en-el-tiempoPerdidos en el Tiempo is the videogame I developed in my free time. It was done with Unity and is available for iOS and Android:
Download it for free for iOS
Download it for free for Android

CambiosUY now available for Android!

CambiosUY now available for Android!

Ok, I should have written this a few months ago, but well, better late than never.

After a couple months of development, CambiosUY is now available in Google Play. Unfortunately Google does not support merchant registration in Uruguay, which means I cannot provide in app purchases in CambiosUY. For this reason, the notifications feature (available for iOS) will not be available until this situation is fixed :=)

I hope you enjoy using the app, and as always, all feedback is welcome!

“The Design of Everyday things” Review

“The Design of Everyday things” Review

Hey there! After more than a year, I’m back with a new post.

Today I wanted to write a brief review about a book that I have recently read and that I enjoyed a lot. The book is called “The Design of Everyday Things” by Don Norman.

In case you don’t know about him, Don Norman is widely known by his research and advocacy in human-centered design. You might have heard of the “Norman doors”, term referred to poor designed doors, that people came up after Norman’s research in the topic.

The book explores how design help us understand the way things work. Sometimes we feel frustrated when we can’t make some products do what we want them to do. Norman argues that this is not the users fault but a poor design of the product.

The book uses concepts from psychology and common sense to explain what a good design stands for.

The interesting about the book is that it takes examples from different objects, products or situations; from everyday issues to problems related to highly sophisticated machines. Plus all of these concepts apply to everything, so instead of being a book addressed just to designers is a book for everybody. Worst case scenario you’ll start to appreciate the design of the things around you.



CambiosUY is out!

CambiosUY is out!

For the last weeks, I’ve been developing my first app in iOS. Last week, surprisingly, I received the good news that the app was approved by Apple (theoretically the store was supposed to be closed by then).

The app is called CambiosUY and allows you to be updated  to the latest currency exchange rates in Uruguay. Some of the functionalities are; it tells you whether it’s a good or bad moment to exchange money, find the closest money exchange to you as well as the more convenient one and lastly, a calculator to calculate how much money you’ll get or need to make the exchange.

You can download it by following the next link:

Web Accessibility

Web Accessibility

A few weeks ago I had the chance to give a small talk about Web Accessibility in the place where I work.

Some of the key points that I talked about were:

  • Web accessibility benefits not only people with disabilities but also improves the usability of a website.
  • Some of the guidelines given by the WCAG are not that complicated to implement, and you are gaining a great number of potential users.
  • The sooner you start to think about accessibility while developing a web site, the easier will it be to implement it.
  • There’s a great number of countries that introduced regulations that require websites to be accessible, specially the government ones.

You can find the complete presentation here and a short video (in spanish) with an example of how a screen reader works here.

Scraping a webpage using ruby

Scraping a webpage using ruby

Scraping a webpage using ruby is very easy.

First, install the ‘nokogiri’ gem by adding it to your gemfile or by executing the following command:

gem install nokogiri

Then, in your controller, open the webpage you want to scrap:

require 'open-uri'

page = Nokogiri::HTML(open(""))

Once you have opened the webpage, you are ready to access the content.

Given the following html:

<div class="term">
    <div class="word">Scraping</div>
    <div class="definition">is a technique of extracting information from websites</div>
<div class="term">

You can get the complete list of terms using the “search” method:

 terms ='.term')

 terms.each do |t|
     word ='.word').first.content
     definition ='.definition').first.content
     puts word
     puts definition

There are several other ways and methods to  help you scrap a webpage using nokogiri. Check the complete nokogiri tutorials to know more.


You can also get the working example from

How to get started with Reddit

How to get started with Reddit

If you haven’t heard of reddit, reddit is a platform for sharing content such as news, posts and basically anything about almost every topic. The users of this site are the ones who make these content more or less visible to others by positive or negative voting it.

As I said, you can find content about almost anything that comes to your mind, and the way to organize it is called ‘subreddit‘. A subreddit is like a category created by a user, and can be as general as ‘Technology‘ or something super specific like photos of  ‘Dogs with cat heads’.

The first time that I went to reddit, I felt a little overwhelmed with so much information, and although I could go to any subreddit by simply searching for it in the search bar, that doesn’t seemed very practical to me. I wanted a more twitter-like experience.

Finally I decided to give it a second try and I signed up to reddit. Creating a user in reddit allows you to subscribe to any subreddit you like.  Then you have a few tabs like ‘hot’, ‘new’, ‘rising’, ‘controversial’ and others that help you read about all your interests altogether, without the need to go to different pages.

TIP: When you create a user in reddit you are automatically subscribed to several subreddits that you might not find interesting. I recommend you to first unsubscribe you to all these subreddits and then start subscribing to the ones you like.

So far, my experience in reddit is mainly positive, there’s a lot of content that I would probably never discover. And although, I don’t think reddit will replace Twitter as my first source of news and articles in the short term, its different approach and the amount of information in it deserves at least a try.

Arduino, clocks and EEPROM

Arduino, clocks and EEPROM

Hi there! It’s been a while since my last post.

Today I’m going to be writing about Arduino. In case you don’t know what Arduino is:

Arduino is a microcontroller used for sensing and controlling things in your environment. Its easiness of use and the fact that it’s open-hardware has made it very popular in the last years.

Right now I’m working on a couple of projects involving Arduino. You’ll know more about them in next posts.

For one of these projects I needed to have a clock in order to store when certain events happened. Luckily Arduino has a library for this purpose:

Read More Read More

Reciclalo: Finally it’s out!

Reciclalo: Finally it’s out!

For the last year I’ve been working on a project to build a web app to help people to find recycling centers in their city. The idea is simple, you choose what you want to recycle and the web app will show you where you can do it. You can also specify your address or use your current location (GPS)  so you can find the closest spots to you.

The data come from open data sources or can be added by the users. If any of the information is incorrect or inaccurate  you can report the spot explaining what’s the problem.

Finally, you can check the trends in the page, for example; top searches, top categories or even top searches that didn’t return any result.

The app was developed using Ruby on Rails and currently it’s only available for Montevideo (Uruguay), but the plan is to extend it to other cities.

Visit it on