For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/multimedia:apps/openSUSE_Tumbleweed/multimedia:apps.repo
zypper refresh
zypper install radiotray-ng
For openSUSE Factory PowerPC run the following as root:
zypper addrepo https://download.opensuse.org/repositories/multimedia:apps/openSUSE_Factory_PowerPC/multimedia:apps.repo
zypper refresh
zypper install radiotray-ng
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/multimedia:apps/openSUSE_Factory_ARM/multimedia:apps.repo
zypper refresh
zypper install radiotray-ng
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/multimedia:apps/15.6/multimedia:apps.repo
zypper refresh
zypper install radiotray-ng
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/multimedia:apps/15.5/multimedia:apps.repo
zypper refresh
zypper install radiotray-ng