Our webshop products do work on mobile devices, but it's best to download them first to a computer and then sync that with your mobile device. Downloading directly to your phone can cause issues - some phones just aren't sure how to unpack/interpret the initial files. Some people have reported success with this method to open and transfer the files.
Note: As of September 12th 2019, we no longer provide official support for our Anki based pronunciation trainers and word lists. You are more than welcome to still purchase and use them, but the support we are able to offer for these products is limited. For supported languages, these materials are already built into the Fluent Forever app.