Initially PDA’s were having functionalities like personal directory, an appointment schedule, camera and games . In 1996, Nokia launched the first PDA with full mobile phone functionality that spawned a new PDA phone, now known as Smartphone . Integration of PDAs with mobile phones gave rise to the smart phone production. The manufactures started to make their products more attractive for the users by developing different applications.
Initially most of the work was carried out on the hardware usability of the mobile phones with limited software applications but later keeping user interaction with computer and the applications used within it, compelled mobile phone companies to take special attention towards mobile applications.
Review of previous studies
Zhong & Michahelles have investigated the Android app store to find out whether it is a long tail or Superstar market. There findings suggested that it is a Superstar market which is dominated by hit/blockbuster apps . Their findings suggested that developers should focus on optimizing apps for small screen sizes of smartphone and provide flexible pricing options. In the long term, the app markets may show different growth structure because of the effects of social networks and the way friends recommend apps to each other .
Petsas et. al investigates the effects of pricing and revenue on popularity of an app and the developer income. Their study indicates that 10% of the apps account for 70-90% of the downloaded apps. This result is attributed to “clustering effect”, which means that user downloads the next app from the same category .
Cuadrado & Dueñas discussed the factors which affects the success of an app store. Apple store follows a closed source and walled garden model while Android store follows an open source model with fewer restrictions. This leads Android store to have more diverse apps but it also causes fragmentation .
Song et. al discusses the user satisfaction in app stores. They conclude that user satisfaction is dependent on the discoverability of apps . User satisfaction is affected by the app store coherence, user reviews and perceived sufficient quantity of apps by the user .
Aguilar et. al investigates deceptive and malware laden apps in Android app store. Authors have come up with a model which can flag an app which is either deceptive or malware . The research shows that the model flagged 9 out 10 potentially harmful apps .
Hyrynsalmi et. al discusses the value creation in smart phone app stores. They studied Apple, Google and Microsoft app store eco systems . Their study identified major factors which affect the value of eco system, which are lock-in, efficiency, novelty and complimentary .
Apple app store is closed source and has strict restrictions for submitting an app. Which has a positive effect on the quality of apps and in-turn increases user satisfaction with the app store. This also increases the novelty and value of the app store, which attracts developers and mobile users to the app eco system. On the other hand, android has a lot of malware laden apps and therefore has lesser attraction for the developers and users. Discoverability of apps also plays an important role in creating a successful app store. Making it easier for the end user to discover apps through their social connections makes them feel comfortable in using the app. In some cases, most of the app downloads were triggered by social factors such as friends downloaded the same apps.
Usability has always been a major issue for development of mobile phones and the features availability for the users. In this regard a lot of research has been done on usability from various perspectives in different times. [16,17,18,19] Usability engineering allows developers to include usability practices in the developing process in order to avoid usability problems and collect information from its users in a more appropriate way . ISO 13407 describes the way of achieving user goals through user centered design in its guide which is considered a best practice .
Usability is a way through which users get experience about an application. Mobile phones are playing an essential role in learning besides communication. M-learning is today’s technology via which users can benefit but success of any application is based on the usability of that application that can be suffered through several issues . Such issues can be:
The design of the application which can be complex and difficult to use.
Highly developed interactive interfaces can have several confusing menus causing users to be lost while exploring the application.
Insufficiency content that the user is looking for.
Difficult design can be hard to remember that finally results in disappointment of the user to achieve the goals.
Information can be difficult to navigate through.
Information and objects used inside an application may not be structured properly.
Such issues can cause the user to get frustrated, disappointed and can eventually make him decide not to use that application again . For a better application, the developer should keep the issues in mind and should try to use the quality components which are as follows 
Learnability: how easy it is for a user to finish their tasks when they use the application for the first time.
Efficiency: how fast they perform the task.
Memorability: how easy it is to remember the use of the interface the next time.
Errors: how many errors the user made while using the application.
Satisfaction: the feeling of the user after using the interface. Did he achieve his goals?
It is good to involve the user from the start of the design phase of an application to the end phase. Using that approach a group of users can be selected and can be authorized to access each option of the application using the “think out loud” technique. It is possible sometimes that this technique may be irrelevant because of different background of users with different experiences which can lead us to multiple feedback and can affect the quality of the application .
As the usage of smartphones have increased in the last couple of years, providing usability assistance to users of mobile phones have not improved as compared to the desktop user experience . Rauch formulates suggestion for developing user assistance for mobile apps . There are different usability issues on mobile platforms, for e.g. inconsistent interaction design, non-user friendly user interfaces, non-user friendly navigation design etc.
. Rauch suggests designing apps for the size and type of mobile display and interface for the actions which the user will perform (keep it minimalistic), develop prototypes for testing designs etc. .
The majority of web content is designed for desktop users, but with a growing usage of mobile users, the same content is now being accessed through mobile phones . Most of the content providers are still providing the same desktop designed content to the mobile users, which is not user friendly for mobile phones . Guirguis & Hassan present a Content Management System (CMS) to deliver user friendly and device adapted content to different types of mobile devices . The CMS adapts to a specific mobile device in 2 ways, first it adapts to the device browser to provide optimum layout of content and navigation, and secondly it perform media adaptation by compressing the contents and providing compatible contents (e.g. video or audio) .
Web experience on mobile devices is poor as compared to desktop users . Shrestha also performed usability evaluation of user web experience on mobile phones . The author conducted an experiment in which users were asked to perform different web browsing related tasks in a laboratory environment . User performance was measured during the experiment. Based on the data gathered through the experiment, the author gave suggestions on how to develop mobile friendly web pages . Shrestha suggested to use clearly visible font and background colour, addition of a search function, use text instead of images, label items and give them titles, use short lists on webpages etc. .
There is no standard approach for the usability evaluation of mobile phone apps . Qiu et al. present an approach to evaluate the usability of mobile phone camera software . They classified usability into four dimensions such as control/action, learnability/memorization, perception, and evaluative feeling . They conducted an experiment on a group of users to use the camera software of different mobile phones . The author measured and observed the behaviour of the users and also used a questionnaire related to the four classified usability dimensions .
Usability is an important factor in the user acceptance of a mobile app . In this research work a mobile app is developed and evaluated . First, a contextual interview in which user uses the mobile app and the feedback from the user is recorded as well . In the second part of the research method, a diary study is performed, in this method the user used the mobile app for a week and then the log files were used to gather data about usage of the mobile app .
The usability of mobile apps can be affected by different factors . Tsiaousis & Giaglis performs research on the effect of environmental factors on the usability of mobile websites . They identified different environmental factors such as visual, auditory, social etc. . A pilot study and experiment was used to measure the effects of different environmental factors on the usability of mobile websites . They concluded that the lighting level, motion and presence of nearby people/objects, nearby sounds and other variables affect the usability of mobile websites for different people .
There is a lot of research work done on providing guidelines for mobile device but in this article the author proposes guideline with metric as well . Hussain & Ferneley identified a set of guidelines from existing literature using the four steps defined by Leavitt & Shneiderman . They used the Goal Question metric (GQM) approach to generate the metrics for each identified guideline . Mobile app developers and operating system vendors should deploy consistent design throughout their app/website/OS . Mobile friendly fonts, colours and more visual elements should be used [21, 6]. Most of the online content is designed for desktop users, which makes it difficult for the mobile user to consume it. Content should be tailored for mobile phones as well, alongside of desktop, especially in cases of audio and video content . Apps and operating system should provide search functionality, which is easily discoverable .
We conducted a survey on a small group of users to look for potential usability problems that smartphone user faces during searching, installing, uninstalling, and updating apps on the iPhone, Android and Windows Phone . This pilot study will form the basis for the later full scale survey.
A group of 10 users with different age and backgrounds were selected and a questionnaire was given to them to fill out. The participants were selected randomly in local market, university and town center. This survey was conducted in May, 2012. All the questions in the questionnaire were multiple choice questions to get unambiguous answers from the participants, see Appendix A.
Selected participants belonged to the following age groups:
2. Adults over 21
3. Adults over 40
After conducting the survey, answers were grouped in the following categories based on education.
a. Basic Education
b. High School/College
c. University Graduates/or higher
The results show that most of the users use iPhone while some used Android and Windows phone. According to the result, we found that user’s satisfaction varies from person to person on different mobile platforms. Most users prefer to install mobile applications instead of using web applications. We found different responses from users about the process of searching, installing and updating apps, some users find the process simple while others had difficulty installing and updating apps. Most of the users, who find paid apps do not want to pay because the process contains too many steps. Mostly users prefer to install and use free apps. Most of the users have installed 10 or less than 10 apps on their mobile phones.
It was evident from the survey that there are some usability issues in the process of searching, installing and updating mobile apps on different platforms. Results from the questionnaire (provided in Appendix A) are shown in the table 1. First column represents the question from the questionnaire while the rest of the columns represent the answers of the 10 participants.
Table of contents :
Chapter 1: Introduction
1.2 Problem Area
Chapter 2: Research Methodology
2.1 Previous Research
2.2.1 Conducting Survey
2.2.2 Survey 1
2.2.3 Survey 2
2.3 Think aloud based experiment
Chapter 3: Previous Research
3.1 Review of previous studies
3.2 Usability issues
Chapter 4: Survey 1
Chapter 5: Survey 2
5.1 Payment for Apps
5.2 Downloading and installation of Apps
5.3 Uninstalling Apps
5.4 Identifying installed Apps
5.5 Updating Apps
5.6 Information about Apps
Chapter 6: Anova Analysis
6.1 One-way anova test
Chapter 7: Think-aloud based Experiment
7.3 Selection of participants
7.4 Usability test materials
7.5 Designing tasks
7.7 Usability Observation scheme
Chapter 8: Experiment results
8.1 Tasks success rate
8.1.1 IPhone task success status
8.1.2 Android task success status
8.1.3 Time spent on Apple Store
8.1.4 Time spent on Android store
8.1.5 Number of taps on Apple Store and Android store
8.1.6 Questionnaire Result
Chapter 9: Discussion
9.3 Work in wider context
Chapter 10: Conclusion