 to be merged into one inbox.The subscription-based Amazon Prime, which includes unlimited streaming of movies and TV shows, is available with a free 30-day trial period.Content formats supported by the first-generation Kindle Fire were Kindle Format 8 (KF8), Kindle Mobi (.azw), TXT, PDF, unrestricted MOBI, PRC natively, Audible (Audible Enhanced (AA, AAX)), DOC, DOCX, JPEG, GIF, PNG, BMP, non-DRM AAC, MP3, MIDI, OGG, WAV, MP4, VP8.