The first viral thing that I ever built was a Visited Countries web app. You know the idea, you have a list of countries, you click the ones you’ve been to and it maintains a map suitable for bragging purposes.
This was a long time ago when people still just had their own blogs and generally were able to insert html straight into what they were doing. The app generated a little bit of html with a link back saying, do you want a map like this? People embedded the html in their blog, visitors also had blogs and did the same.
The hosting infrastructure back in those days of my blog was a desktop computer in the broom closet of our office. It was attached directly to a cable modem that was capable of communicating with the internet at the blazing speed of 2Mbs.
We noticed the app had gone viral because of the noise the ventilator of the computer made (before it died).
A few startups later and now we have Visited Countries working as a spreadsheet. This is the best version yet! Spreadsheets are awesome.
Of course you get a map:
But the nice thing about it is that you also have a tab in the spreadsheet with a list of the actual countries. And that list has a comment column that you can use for whatever you want:
By default it will show the comment if set if you mouse over the country, but since it is all controlled by just a little bit of code, you can modify whatever you want. Change the colors, change the countries, the names of the continents, it is all super easy. You can even change the projection of the map!
Take it for a spin here: