Mobile devices and mobile computing have made tremendous advances and become ubiquitous in the last few years. As a result, the landscape has become seriously fragmented which brings lots of challenges for the mobile development process. Whilst native approach of mobile development still is the predominant way to develop for a particular mobile platform, recently there is shifting towards cross-platform mobile development as well. In this thesis, a survey of the literature has been performed to see the trends in cross-platform mobile development over the last few years. With the result of the survey, it is argued that the web-based approach and in particular, hybrid approach, of mobile development serves the best for cross-platform development. Using the hybrid approach, a prototype application has also been developed and built into native application for different platforms. This has helped to get a better insight about the domain of cross-platform mobile development and its main advantage of the unification of the development and testing process. The results of this work indicate that even though cross platform tools are not fully matured they show great potential and reduce the cost associated in developing native mobile applications. Cross-platform mobile development is equally suitable for rapid development of high-fidelity prototypes of the mobile application as well as fairly complex, resource intensive mobile applications on its own right. As the upcoming future trends and the evolution of HTML5 continues to redefine the web, allowing its growth as a software platform, there remains great opportunities for cross-platform mobile development and hence provides an attractive alternative for the native mobile development.

This thesis has taken part as an experimental development within the Learning Ecology through Science with Global Outcomes project. It introduces the area of cross platform mobile application development and provides a possible solution for tackling the current fragmentation of mobile devices and platforms for data collection. During the process, a mobile data collection prototype was designed, implemented and deployed on Android, iOS and Windows Mango by using standards and web standards such as HTML5, CSS3, XForms and JavaScript. The deployed prototype was then tested with users in order to collect the necessary data to help answer the questions that were formulated. The results indicate an ease of use of the prototype in relation to cross platform development and also shows potential benefits such as less code and time. Cross platform development provides a way to counteract the current fragmentation between mobile platforms.

During the last ten years the market for smartphones has grown drastically. Because of the current state of the market with different operating systems many smartphone applications need to be developed for several platforms. With this thesis, the goal was ultimately to contribute to the understanding of cross-platform development as a way of developing smartphone applications. React Native has been evaluated as a framework with which development is done for both Android and iOS using the same code. To study React Native as a framework, a smartphone application for Android and iOS was developed at an Uppsala based IT-company with expertise in web services, smartphone applications, and online gaming. Furthermore, performance tests and user tests were conducted in which React Native was compared to native applications and applications developed using Xamarin (similar cross-platform development framework owned by Microsoft). It was evident that using the same code for both Android and iOS was time saving. However, the performance tests results showed that applications developed with React Native did not perform as well as the native and Xamarin versions. Leading to the conclusion that choice of framework when developing cross-platform applications need to take into consideration performance, development time, and programming language preference.

Today, there are a handful of different platforms for mobile phones. Writing an application natively for each mobile operating system is time consuming and expensive. This situation has created a need for using cross-platform frameworks, that allow programmers to create an application once and run it on all platforms. The problem is that it is not certain whether cross-platform apps can fully replace native ones, or if by using cross-platform tools some desired qualities are lost. Investigating this issue would allow to find out which one of these two application development methods is better, or in which situation it is better to choose one over the other. Such knowledge would allow to decrease development time and costs. Companies that create mobile applications on a daily basis have expertise in this area. Thus, thirteen interviews were done with thirteen distinct businesses in order to research this problem. The results showed that native development produces higher quality applications, but there are some situations where it might be better to use cross-platform frameworks.

Mobiltelefoner innehåller idag en stor mängd information som är av stort forensiskt intresse. Att skydda informationen i sin telefon är en självklarhet för många och utvecklarna av de mobila operativsystemen lägger nu större vikt på säkerhet och skydd av information. Kryptering är idag standard i de flesta mobiltelefoner och det leder till problem vid utvinning. Arbetet tar upp och jämför hur kryptering hanteras av iOS, Android och Windows Phone och vilka tillvägagångssätt som finns vid utvinning av data genom att kringgå skärmlåsen som krävs för att krypteringen ska fungera. Arbetet ger även en inblick på molnlagring i och med att det blir allt vanligare och kan komma att bli mer relevant för forensiker eftersom telefonerna blir allt svårare att utvinna data ifrån. Dessutom ges en liten inblick på forensiska verktyg som finns idag, vilka brister de har och vad som är oklart hos dem.  Frågeställningarna har besvarats genom att en grundläggande litteraturstudie genomförts för att få den bakgrundsfakta som krävs. Därefter gjordes det experiment för att visa på brister i de forensiska verktygen. Avslutningsvis svarade två it-forensiker från polisen på intervjufrågor via mail, det gjordes för att lyfta fram problematiken och visa på hur situationen ser ut i arbetslivet idag.  Arbetets resultat visar på att alla operativsystem ger, beroende på hur användaren har anpassat telefonen, möjlighet till fullt skydd mot utvinning. Och därmed klarar de forensiska verktygen som finns idag inte av att utvinna någon relevant information ifrån de senaste mobiltelefonerna. Som forensiker borde man utnyttja att molnlagring börjat användas mer och mer, då det där kan finns mycket bra information. Slutsatser som kan dras efter arbetet är att det behövs nya metoder för att utvinna data ifrån mobiltelefoner då de metoder som tidigare använts inte är kompatibla med de senaste telefonerna på grund utav de krypteringsfunktioner som används. Det finns metoder som kan fungera, men dessa metoder fungerar bara med rätt förutsättningar, vilket gör att det inte är en lösning som man alltid kan applicera. Forensiker borde även utforska möjligheten att få fram information ifrån molnlagringstjänster ifall data på telefonen är oåtkomlig för alla utom ägaren. Arbetet syftar inte till att ta fram nya metoder för utvinning eller arbetssätt inom det stora området forensik, utan kartlägger problemområdet inom mobilforensik och ger förslag på och diskuterar möjliga lösningar.

A problem with having a fast and wide production of different platforms for mobile devices is that you can’t code for one and deploy on all devices at the same time. This thesis is focused on cross-plat1form development environments for smartphones and mainly to see what options there are on the market. This report will investigate how well a cross-compiler solution compares to hybrid cross-platform development. To do this we took a closer look at their architecture and then compared this with the results from different tests made. All the tests were made on the same smartphone to ensure fairness between them. All the tests strive to be as equal as possible even though the languages might differ from each other. The tested frameworks were PhoneGap, Qt, Unity3D and GameMaker. The different tests were about performance, power consumption, difficulty in accessing web browsers to perform HTML parsing and lastly to see if the platforms can access different native APIs such as the camera and accelerometer. The previously mentioned topics were compared between all the frameworks. We also compared the documentation found on their webpage to figure out which is the easiest to get started on.

The diploma thesis answers set questions that relate to two different distribution environments, the two options for developers to directly offer their mobile applications to the end users. Distribution is being conducted in the App Store and Google Play application stores, where only such applications that oblige basic requirements can be released and provided to customers. The requirements, official sources of information and support services of the two providers are analyzed in the theoretical part of the thesis. Processes revolving around the application distribution itself are described in the following practical part. Distribution consists of processes from the developer account registration to submitting the application for a review or a check. Sufficient knowledge base could be gathered not only due to a proper exploration of the issue, but also due to an actual application release accomplished by the author. A cross-platform mobile application to be released has been developed solely for the purposes of this diploma thesis. The application has been built in two platform specific versions. Whilst publishing it, an emphasis was laid on keeping the conditions as similar as possible to achieve viable case study results. The application release represents the case that produced all data that enabled a direct comparison and overall evaluation of the different developer settings at the end of the thesis. Findings and conclusions of this thesis can be used by developers and other interested parties that are looking for an integrated source of information that regards releasing a cross-platform mobile application on iOS and Android platform.

This master thesiss goal is to map available tools for support of cross-platform native mobile app development. Main goal of thesis is to choose such tool and present it in form of app development. To accomplish this goal several criteria with different importance have to be defined. These criteria are used for choosing of most suitable tool. This thesis has two outputs. First one are criteria that can be used again or amended for some similar tool rating, like this one. Second output is cross-platform mobile app developed with Xamarin tool. Structure of this thesis copy secondary goals that support main goal: mobile OS are presented, name cross-platform native app is defined, define criteria, describe selected tools, rate them and demonstrate development of simple app on selected tool.

<div>With the increased evolution in technology over the past decade, there has been a gradual inclination towards utilizing advanced tools, like location-based applications which incorporate features such as constant route or traffic updates with Global Positioning System (GPS), among</div><div>others, which aid in smooth living. Such applications gain access to private information of users, among their other life hack qualities, thus producing a highly vulnerable ground for data exposure such as current location. With the increase in mobile application-based attacks, there exists a</div><div>constant threat scenario in terms of criminal activities which pose an ultimate challenge while tackling large amount of data. This research primarily focuses on the extent of user-specific data that can be obtained while forensically collecting and analysing data from Waze and HEREwego</div><div>applications on Android and iOS platforms. In order to address the lack of forensic research on the above mentioned applications, an in-depth forensic analysis is conducted in this study, utilizing Cellebrite, a professional tool to provide and verify the evidence acquired, that aid in any digital forensic investigations. On the Waze application, 12 artifacts were populated on the Android device and 17 artifacts on the iOS device, out of which 12 artifacts were recovered from the Android device (100% of the artifacts populated) and 12 artifacts from the iOS device (70.58% of the artifacts populated). Similarly on the HEREwego application, 14 artifacts were populated on the Android device and 13 artifacts on the iOS device, out of which 7 artifacts were recovered from the Android device (50% of the artifacts populated) and 7 artifacts from iOS device (53.84% of the artifacts populated).</div>

The main goal of this work is to design and to implement a mobile application for drums training. The application must be capable of displaying drum notation of different grooves from various music styles, playing audio examples of those grooves and also analyze and evaluate drumming skills of drummers. The main method for audio processing is discrete wavelet transform. Results show true value rate above 96%.