You can download and install eScan on your iPhone or iPad from iTunes as well as from the following link - http://www.escanav.com/english/content/products/escan_mobile/escan_mobile-ios.asp
Note – The above link will re-direct you to Appstore / iTunes for software download. Additionally, you can purchase the license key from the above link if you have already downloaded eScan App on your iPhone or iPad .