If you can't open these links to the Iridium GO exec App in the Apple App Store or Google Play Store, or by searching for Iridium GO exec, it may not be available in the country App store you are in or have setup your account with.
Alternatively, please use an Android device to download and install it directly from Iridium.
To do this:
Open this File Download Resource on the Iridium website.
The download should begin automatically, or click to start it manually.
When it has been completed, open the Downloads folder in your browser and tap on download to open it.
Follow the prompts to install.