Ofter you feel the need to have some contents already downloaded when you access them. That is the case if you are using a 3G connection like mine where the traffic is limited to 200mb per month or eventually if your 3G is very slow.
Several Apps like Spotify, Google Maps, YouTube, Facebook, Google Plus or other real time streaming application allow you to Preload content while you are on a WiFi connection so that when you are in a 3G you can access them from your system storage or SD card memory.
For Spotify you may download playlists and for Youtube you can change the settings to allow Preloading.
Lets see in YouTube :
> In the top right corner click in the 3dotted button and access Youtube Settings
> Click on Preloading.
> You can enable the Preloading for your channel subscriptions or just for the videos where you click "Watch Later"
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