When the app will not install

"For your security, your phone is not allowed to install unknown apps from this source"

Expected the first time. Tap Settings in that message, turn on Allow from this source, press back and install again. The permission belongs to the app doing the installing — your browser, or Downloader — not to us.

"App not installed"

Usually one of three things:

• An older copy is already there. Uninstall it and install again. Your activation is not affected; it belongs to the device.
• The download did not finish. A part-downloaded APK fails at the end of the install. Delete it and download it again.
• The device is too old. The download page states the minimum Android version. Below it, the file will not install at all.

"Downloads are blocked by your Download Settings."

An Android setting, not ours — the device has been told not to download on the current connection. Change it in the device's download settings, or connect to Wi-Fi.

Downloader on Fire TV does nothing after the code

Check the code first: a remote keyboard is easy to get wrong. If it is right and still nothing happens, the code is not set up on your account yet — tell us and we will fix it.

There is no space

A stick with a full drive fails part-way through with no useful message. Uninstall something you do not use and try again.