The current default theme is [Vier](https://github.com/friendica/friendica/tree/master/view/theme/vier) but there are numerous others.
Have a look at [friendica-themes.com](http://friendica-themes.com) for an overview of the existing themes.
In case none of them suits your needs, there are several ways to change a theme.
-If you need help theming, there is a forum @[ftdevs@friendica.eu](https://friendica.eu/profile/ftdevs) where you can ask theme specific questions and present your themes.
So, how to work on the UI of friendica.
<?php
/* meta informations for the theme, see below */
+ use Friendica\App;
+
function duepuntozero_lr_init(App $a) {
$a-> theme_info = array(
'extends' => 'duepuntozero'.
Adopt the CSS of the theme accordingly.
And iterate the process until you have the theme the way you want it.
-*Use the source Luke.* and don't hesitate to ask in @[ftdevs](https://friendica.eu/profile/ftdevs) or @[helpers](https://forum.friendi.ca/profile/helpers).
+*Use the source Luke.* and don't hesitate to ask in @[developers](https://forum.friendi.ca/profile/developers) or @[helpers](https://forum.friendi.ca/profile/helpers).
## Special Files
If the original author is no longer working on the theme, but a maintainer has taken over, the maintainer should be listed as well.
The information from the theme header will be displayed in the admin panel.
+The first thing in file is to import the `App` class from `\Friendica\` namespace.
+
+ use Friendica\App;
+
+This will make our job a little easier, as we don't have to specify the full name every time we need to use the `App` class.
+
The next crucial part of the theme.php file is a definition of an init function.
The name of the function is <theme-name>_init.
So in the case of quattro it is