This app is for AT&T landline voicemail, not mobile phone voicemail. Make sure you have your AT&T home voicemail PIN prior to downloading this app. Voicemail Viewer makes it easier to stay on top of your Voicemail or Unified Messaging voicemail messages directly from your iOS device. Like looking at messages in your email inbox, you can check your AT&T Voicemail messages visually, choosing the order in which you listen to them or even reading your messages as voicemail-to-text. For more information, visit our web site at att.com/vmviewer. If you are a Voicemail or an Unified Messaging customer and are having trouble signing into or using this app, please contact us at 800.288.2020 (Voicemail) or 888.300.6500 (Unified Messaging) and be prepared to provide your landline phone number associated with your mailbox, the device you are using to access the app and the problem that you are experiencing.