Cisco AnyConnect offers access through a secure tunnel (VPN) to allow iPhones/iPads users to access their e-mail, files, and remote desktops.

Compatibility: Requires iOS 6.0 or later. Compatible with iPhone, iPad, and iPod touch. This app is optimized for iPhone 5.
Cisco AnyConnect provides reliable and easy-to-deploy encrypted network connectivity from any Apple iOS 6 or later device by delivering persistent corporate access for users on the go. Whether providing access to business email, a virtual desktop session, or most other iOS applications, AnyConnect enables business-critical application connectivity. Through the use of Datagram Transport Layer Security (DTLS), TCP-based applications and latency-sensitive traffic (such as voice over IP [VoIP]) are provided an optimized communication path to corporate resources.
Additionally, AnyConnect support IPsec IKEv2 with Next Generation Encryption.
Please note that AnyConnect for iOS requires a Cisco Adaptive Security Appliance (ASA) running software image 8.0(3).1 or later. The ASA requires an AnyConnect Mobile license (L-ASA-AC-M-55XX=), as well as either an AnyConnect Essentials (L-ASA-AC-E-55XX=) or AnyConnect Premium Clientless SSL VPN Edition (L-ASA-AC-SSL-YYYY=) license, where XX is the last two digits of your ASA model number and YYYY is the number of simultaneous users. AnyConnect Mobile and Essentials licenses are enabled per ASA, there is no per user charge for either of these licenses.
DigitByte Software for Windows, Mac, iPhone, iPad, iPod – free download