foen is made by sun-dive. There is no company office and no call centre; there is a person, and a public repository.
There is no email address here on purpose: a published address is a spam magnet. Messages go straight to the operator and nowhere else.
Problems with the software
Use the form and say which device and browser. A message that says what you did and what happened instead is enough.
Advertising and business
Use the form. Direct placements on the idle screen are available to businesses whose products suit a free telephone.