roarphone: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/roarphone - from package: roarclients

You may install the required package with command apt-get install {package}
Error in other languages:
roarphone: bevel nie gevind nie
roarphone: comandă negăsită
roarphone: comando não encontrado
roarphone: commande introuvable
roarphone: command not found
roarphone: käsku ei ole
roarphone: không tìm thấy lệnh
roarphone: komanda nerasta
roarphone: Kommando nicht gefunden.
roarphone: kommandot finns inte
roarphone: komut yok
roarphone: nie znaleziono polecenia
roarphone: níor aimsíodh an t-ordú
roarphone: no se encontró la orden
roarphone: no s'ha trobat l'ordre
roarphone: opdracht niet gevonden
roarphone: parancs nem található
roarphone: perintah tidak ditemukan
roarphone: príkaz nenájdený
roarphone: příkaz nenalezen
roarphone: команда не найдена
roarphone: командата не е открита
roarphone: 命令找不到
roarphone: コマンドが見つかりません