You can easily post photo, PDFs and Office documents from online storage, photo, reader and Office apps:
 
For iOS:
  1. Open the photo or document you want to share.
  2. Tap the Share or Open In link or icon (will vary by app).
  3. Look for and tap the RingCentral icon in the iOS share extension. You may need to turn on the app by tapping More.
  4. Search for and select the conversation to which you want to share.
  5. Tap Share.
For Android:
  1. Open the photo or document you want to share.
  2. Tap the Share icon (will vary by app).
  3. Look for and tap the RingCentral icon in the Android share extension.
  4. Search for and select the conversation to which you want to share.
  5. Type a message to accompany the photo or file.
  6. Tap SEND.