To the customers who use an SD card on Android 4.4 and later.Due to the specification change of Android 4.4 and later, writing to SD card is restricted by Android.A library can be newly created in the location where writing to SD card is allowed by Android 4.4 and later ((sdcard)/Android/data/jp.pioneer.prosv.android.rbm/files).Note: If those who use an SD card on Android 4.3 and earlier update to Android 4.4 and later, track information will not be displayed due to the above-mentioned restriction.If you encounter such a problem, please import the tracks in the Android device or in rekordbox (Mac/Windows) to rekordbox (Android) again.Note: An issue where some Android devices cannot be connected to CDJ using a USB cable if such a device is updated to 4.4 or later has been identified.If you cannot connect CDJ to your mobile device using a USB cable, please try connecting them via Wi-Fi.rekordbox is a music management App for Pioneer DJ products.You can transfer music files from your Mac/Windows to this App to prepare for your DJ performance such as creating playlists, setting cue points, and so on.Changes and settings that have been made on your Android device can be written back to rekordbox on your Mac/Windows for further editing and playback.You can also play music files in theAndroid version of rekordbox with Pioneer DJ products that support this App.(currently CDJ-TOUR1, CDJ-2000NXS2, CDJ-2000NXS, CDJ-900NXS, XDJ-1000MK2, XDJ-1000, XDJ-700, XDJ-RX2, XDJ-RX and XDJ-AERO are supported.)Main features :Transferring music files from rekordbox on your Mac/Windows to this App via Wi-Fi.Changes and settings that have been made on this App can be written back to rekordbox on your Mac/Windows for further editing and playback.Importing existing music files from your Android device.Setting memory cues/loops, hot cues/loops. Analysing and editing beat grids/keys.(Please note that features such as memory cues/loops and hot cues/loops are not included in XDJ-AERO.)Editing comments and rating tracks.Creating and editing playlists.Playing music files in rekordbox with Pioneer DJ products that support this App.(USB and Wi-Fi connection can be used with CDJ-TOUR1, CDJ-2000NXS2, CDJ-2000NXS, CDJ-900NXS, XDJ-1000MK2, XDJ-1000, XDJ-700 and XDJ-RX. USB connection can be used with XDJ-RX2. Wi-Fi connection can be used with XDJ-AERO. A Wi-Fi router is required to connect this app to CDJ-TOUR1, CDJ-2000NXS2, CDJ-2000NXS, CDJ-900NXS, XDJ-1000MK2, XDJ-1000, XDJ-700 and XDJ-RX via Wi-Fi.)We recommend you install the Mac/Windows version of rekordbox (Ver.4.0.6 or later) on your computer to use this App more effectively.The Mac/Windows version of rekordbox can be downloaded for free from Pioneer DJ rekordbox web site: http://www.rekordbox.comPlease note that Pioneer DJ does not guarantee that this App works without any issues on any devices.