If your device is Android version Lollipop 5.0, it will only have the option to save to an “Internal” or “External” location in the app Settings menu, not a customised download folder.
In the Settings menu, if internal is chosen it will download to folder 7digital/track on your device. If external is chosen it will download to the SD card folder 7digital/track
If your device is Android version 4.4 or lower, you can customise the download location.
Go to the app settings menu and tap “Storage location”
Navigate to a folder you want to download to and tap “Select current folder”