You can share Dropbox folders from the website or from any mobile device, computer or tablet. If you want to share folders from Android phone, download and install 'Dropbox' folder on your Android phone and open the app. You will see all your photo and video folders. There are many ways to tap 'Invite people to collaborate'. You can either press and hold the folder to tap it or tap 'Down arrow' icon located in front of the folder. You can also open folder and tap 'Share' icon located at the top right corner on the screen.