Even though there are certain specific areas where device specific applications are appropriate, it is usually more advisable to build your application which is platform specific rather than device specific. Both Apple and Android provides design guidelines for creating "universal" applications. In other words you can create an iOS application that will work fine on both iPhone and iPad and similar can create Android application that works on Android Mobile Phone as well as on Tablet devices.

Figure: Creating Platform specific Application that works on both Mobile or Tablet Device

Though you might just need to support one platform today it is noticed that as the time went along, may organizations have ended up in a position wherein there is a need to support multiple platforms. It is very important for organization to determine if there will be such a need in future and if so cross-platform mobile architecture is still a good choice.

If you want to support multiple platforms from day one or might have a need to do so in future, Cross Platform Mobile Application Architecture should be examined to determine if this will be appropriate choice for your project.

Figure: Cross-Platform Mobile Application Architecture

While majority of code base and logic between cross platform applications there is always need to change the user-interface depending on the Mobile devices you are planning to support.

Depending on your situation there may be several mobile architectures: Native Mobile Application, Hybrid Mobile Application or Mobile Web App approaches that might fit your business. In coming sections we have identified advantages and disadvantages for each Mobile Architectures.

SOAP is a protocol specification for exchanging structured information (as shown in diagram below) in the implementation of Web Services

The acronym REST stands for Representational State Transfer, this basically means that each unique URL is a representation of some object. You can get the contents of that object using an HTTP GET, to delete it, you then might use a POST, PUT, or DELETE to modify the object (in practice most of the services use a POST for this).

Each of those two frameworks has its own features and shortcomings.

	SOAP	REST
Advantages	» easy to consume (XML) » development tools » built-in error handling (faults) » built-in type checking » extensible » standardized	» lightweight » human readable results » easy to build » closer in philosophy and design    to the web
Disadvantages	» more difficult » heavyweight » verbose » harder to develop	» tied to HTTP » lack of standards support for security,    policy, reliable messaging, etc. » assumes a point-to-point    communication model

For this we have laid out a quick way to find out the best Web Services Protocol for your Mobile application depending on your business needs.

• EASE OF IMPLEMENTATION AND MAINTANENCE
  Winner: SOAP (As it is older technology and hence widely available in Enterprises)
• HEAVYNESS/LIGHTNESS
  Winner: REST (REST is definitely lightweight compare to SOAP and one can easily implement and consume JSON service which matters a lot for mobile applications.)
• CACHING
  Winner: REST (Since HTTP based / Rest-ful APIs can be consumed using simple GET requests, intermediate proxy servers / reverse-proxies can cache their response very easily. On the other hand, SOAP requests use POST and require a complex XML request to be created which makes response-caching difficult.)
• SECURITY
  Winner: SOAP/REST (Both SOAP and REST have equal advantages and disadvantages in security area)

REST-based services are more adequate and preferred choice for iOS and Android Mobile App development needs. If you are developing web-services from .scratch you should consider using REST-based services for your Mobile project. If you already have SOAP based services ready you should evaluate if they are lightweight, and there are no issues in caching and proxy generation for consumption. If that's the case SOAP based services can be used in this case.

• The interface should be easy to use from the very first time the user interacts with it
• In a perfect User interface, user should never be allowed to commit mistakes
• The interface should be simple, and unnecessary functionality should be avoided
• The visual design and the layout should be easy and uncluttered
• Visibility of the important information should be maximum
• Users should be always in control of the interface
• The navigation should always be narrow and shallow
• The vertical scrolling should be minimized as much possible and horizontal scrolling should be avoided
• Useful and interactive error messages should be provided to users
• It should be ensured that the system response time is fast
• Wizards should be used to simplify complex interactions

1) Analysis of User requirement:

Ensuring that the connection between the backend system and the server is done properly and secured enough is very important.

2) Conceptual Design, Prototypes, and Evaluation:

It is necessary to make sure that data exposure and replication is as fewer as possible throughout the communication stack.

3) Design and Implementation:

The communication happening through wired or wireless networks from the devices is secured or not. It is important to check with the security of communication channels.

4) Conducting Usability Evaluation:

Ensuring security of encrypted device resident data is also important.

5) Launch and Maintenance:

Application security is also equally necessary ensuring proper application permissions are taken; data access related security is properly done; etc. It involves use of various software, hardware, and procedural methods to protect the mobile apps from the external threats.

1) Data Transmission Security:

Ensuring that the connection between the backend system and the server is done properly and secured enough is very important.

2) Operational Data Security:

It is necessary to make sure that data exposure and replication is as fewer as possible throughout the communication stack.

3) Security of Communication Channel:

The communication happening through wired or wireless networks from the devices is secured or not. It is important to check with the security of communication channels.

4) On-Device Data Security:

Ensuring security of encrypted device resident data is also important.

5) Application Security:

Application security is also equally necessary ensuring proper application permissions are taken; data access related security is properly done; etc. It involves use of various software, hardware, and procedural methods to protect the mobile apps from the external threats.

6) Authorization and Authentication:

It is important to make sure that secure verification of user identity and roles is being performed for the security of data.

7) Remote Administration:

This includes – ensuring central IT control over access, policies and profiles of apps and users on the device.

Data Security should be performed with proper overall planned strategy and risk assessment that enables to identify the risks involved. Once planning and risk assessment is done, the data security system should be bought into action immediately.

A good effective Data Security System involves a combination of proper technical measures, effective physical security, and a well knowledgeable staff.

Some common security measures necessary to be taken care of are:

• Regular back up of the data should be taken and multiple backup copies should be stored safely
• When the mobile device is left alone, password protection system should be always activated
• Protecting the mobile device from any kind of physical damage to secure the data in it

Securing the data efficiently involves many steps and it is very time consuming too. But it is always better to secure data efficiently than actually losing the important data.