You can use the YouTube Studio app on your mobile phone to add custom thumbnails to your videos. Here are step-by-step instructions: https://goo.gl/fm9KNQ . Hope it helps!
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
You can use the YouTube Studio app on your mobile phone to add custom thumbnails to your videos. Here are step-by-step instructions: https://goo.gl/fm9KNQ . Hope it helps!