Create your own Apps - II

On this page you'll learn all the technological background info you'll need to create a working app.

App compatibility

We'd like to offer web apps that are compatible with all major platforms (Windows, MacOS, Linux, ...) and all important browsers (Firefox, Internet Explorer, Chrome, Safari, ...). Please make sure to test your app with all of these, or ask friends to do the testing for you.

Please avoid using technology that requires plug-ins on the client side (Flash, Silverlight, Java, ...). Apps using such technology will be accepted, but they may get lower ratings as they may cause problems on some devices.

You may use any HTML variation, although we recommend using at least HTML 4.x and CSS. Using HTML5 and CSS3 is cool, but it's not required. Use only HTML5 features that are supported by all major browsers.

It's not required that your apps use valid HTML or CSS, nevertheless this is always good to improve compatibility and to avoid problems.

App languages

You app can use any language as a default language. The currently used language on is transmitted to your app using the "app_lang" variable. It is recommended to use this language at startup if it's available.


Apps are displayed within an <iframe> element on The Iframe is calling your app using the URL you'll enter later on using the developer tools, plus some input variables.

Currently supported input variables are:

the language currently used by the user (en, de, fr, ...)

The complete URL called by the Iframe may look as follows:

Please note that we don't offer any application hosting facilities, at least not for now. This means that you'll also need a server or a web hosting service to install your apps.

App code apps can be either static HTML files or dynamic "web apps".

If you'd like to go with static HTML files then use your favourite HTML editor or code your HTML files manually if you want. You may also use Javascript to make your web app interactive or more attractive.

You may use Perl, PHP, Python, .Net or any other language to create dynamic web apps.

A web app page could look as follows - this example page is loading two CSS files from, these should be used if you'd like to use the look and feel of the standard apps. You may remove these two lines if you'd like to go with your own design or look and feel.

Please note that all web apps should use an UTF-8 character encoding. Using a different encoding may work too, but this might cause problems with future API releases.

   <meta charset="utf-8">
      <link rel="stylesheet" type="text/css" href="" media="all">
      <link rel="stylesheet" type="text/css" href="">
         a {color:#990000}
         h1,h2,h3,h4,h5,h6 {color:#990000}

App screen size

The standard size for apps is 920 * 480 pixels. This looks quite good on most desktop computers, laptops and tablets.

Don't create any apps using a width larger than 920 pixels, as these will probably not be approved. Your app height may be higher than 480, the Iframe will then display a scrollbar. Don't forget that the scrollbar will probably reduce your app width by 10 to 20 pixels, so it's good to make sure it also works fine in a 900px Iframe.


Some ad providers, such as Google, do not allow to put ads into Iframes. Putting Google ads inside an app on would also get you (and maybe even us) into trouble as the maximum allowed number of ads blocks per page could be exceeded. Too many ads or offensive ads inside an app will probably lead to an app disapproval.

Design guidelines

  • Option 1: use the same design as the default apps
  • Option 2: create your own, cool app design
  • Just don't use one of these crappy 1990s web looks!

What's next?

Move on to the next page and learn how to publish your app.


App rules

  • Make sure your app is useful and fits well on this site
  • Games, fun apps and utilities are also allowed
  • Make sure your app looks nice
  • Create a nice app icon (you may use our templates)
  • Create a nice app desciption
  • Translate your app into other languages (you may ask other people for help)
  • No misleading icons, descriptions or screenshots
  • No porn, nothing nasty, no illegal stuff, ...
  • Never ask for user information, passwords, signups, ...
  • Don't try anything nasty (cross site scripting, accessing information from, ...)