\begin{frame}
  \frametitle{Freie Software auf Computern}
    \begin{columns}
        \begin{column}{5cm}
            \begin{center}
                \includegraphics[height=0.2\textheight]{../../img/firefox.png} \\
                Firefox \\
                \vspace{0.1\textheight}
                \includegraphics[height=0.2\textheight]{../../img/libreoffice.jpg}\\
                LibreOffice
            \end{center}
        \end{column}
        \begin{column}{5cm}
            \begin{center}
                \includegraphics[height=0.2\textheight]{../../img/thunderbird.png} \\
                Thunderbird \\
                \vspace{0.1\textheight}
                \includegraphics[height=0.2\textheight]{../../img/vlc.png}\\
                VLC Media Player
            \end{center}
        \end{column}
    \end{columns}
\end{frame}

\begin{frame}{Freie Software auf dem Smartphone}
  \begin{columns}
    \column{6.5cm}

    \textbf{F-Droid}\\
    Android-Appstore für freie Software

    \vspace{0.5cm}

    \textbf{iOS Open Source Apps}\\
    \url{https://github.com/dkhamsing/open-source-ios-apps}

    \column{5cm}

    \begin{center}
      \includegraphics[width=2cm]{../../img/F-Droid_Logo_2}
    \par\end{center}
    \begin{center}
    \par\end{center}
  \end{columns}
\end{frame}