Link to the Sigfox Repeater App : https://play.google.com/store/apps/details?id=com.adeunis.RepeaterApp
You can install the android app without going through the Google Play Store.
It is necessary to allow the installation of uncertified application in the settings of your phone.
Copy the .apk file to a directory on your phone
Then select this file.
The program installs on your phone as if you had been through the Google Store.