What is the application? Application or its shortened form known as App is a software that allows you to do many things with it. Mobile applications are known as Mobile App. Most of them can be downloaded at low cost and even for free. Applications are divided into categories such as Web, Native, Hybrid, Killer and Legacy. Applications are actually the main structure and pillar of smart mobile phones. It was in 2007 that with the arrival of the iPhone and the presence of the App Store the following year, as well as Android and Google Play in 2008, applications became the main policy in the mobile phone revolution. which made the use of mobile phones unimaginable without their presence. Today, all industries, businesses and technologies would not be very effective without the presence of these important options. Due to the versatility and applicability of applications in tourism industries, games, social networks, media, various businesses, etc., they have become a permanent and essential member of these businesses. The importance of application design Along with the expansion of smart devices such as mobile phones and tablets and the design of mobile applications in all fields, the number of mobile users is increasing day by day. The use of personal computers has decreased compared to smartphones. In fact, today, the most number of Internet access is from mobile phones and tablets, and this number is increasing day by day. Mobile phones are the best means of accessing information if you have products or services to offer and you want your products and services to be seen and people can find you and use them, designing a dedicated Android and iOS application is the best way to Achieving your goals is an application that has an attractive appearance, will sell more, and designing a dedicated application will help your business succeed a lot. Stunning statistics of Internet users' use of applications According to comScore statistics, 87% of Internet users use applications and only 13% use websites. This means that most of the internet users tend to fulfill their needs through applications and if you are a business owner and you still don't have a mobile application for your business, you will soon lose many of your users and a market full of customers. will give Build an Android application Android application development has become one of the main goals for online businesses today. The widespread use of mobile phones and its continuous use among people has given business owners and marketers access to a new and valuable source of information in the field of customer behavior and needs, and the correct use of these statistics and information plays an effective role in improving the future activities of businesses. And will update mobile marketing strategies. In addition to improving work methods, mobile application also improves business, positive interaction with customers, saves time and advertising costs, and generates income. There are many languages for building and designing Android applications, including Java, Kotlin, C++, and Corona. But among them, Java is considered a more formal and common choice. Because it is supported by Google and most applications other than games are made with Java or Kotlin. Next, to build an application in the Android environment, the following steps must be implemented: • Download the Android Studio app • Implementing the program and starting a new project • Editing messages in the Main Activity section • Add buttons to Main Activity • Production of the second version of Main Activity • Write the onClick button • Application testing Building an application on the iOS operating system As you know, iOS is known as the operating system of iPhone, iPad and iPod, and Apple creates tools and resources for these devices. As an application developer, do programming with Native languages such as Swift or Objective-C, as well as the Native platform using JavaScript or C#. Of course, to develop the relevant application, you must use a Mac computer and the latest version of Xcode. It is worth noting that Xcode (Integrated Development Environment) is known as the integrated development environment for Mac and iOS and is a graphical interface for writing and designing iOS applications. To develop the application in a native mobile environment, Apple suggests using the modern Swift program, which we described above. It will be possible to develop the application using the iOS software development kit (SKD). Through this kit, tools, technologies, capabilities and languages are searchable. Some of the must-have kits are Cocoa Touch, which includes things like UIKit, GameKit, PushKit, FoundationKit, and MakeupKit. These frameworks and others allow the user to manage many things such as sound options, camera, music search and many other things. On the other hand, over the past several years, capabilities have been added to this kit, including augmented reality (Augmented Reality) and machine learning (Machine Learning) with the central core of ML. Next, the application development environment should be created according to the following steps: • Download Xcode • Run Xcode and generate a new project • Familiarity with Xcode • Build and run the application using the built-in iOS emulator that includes Xcode. The simulator provides the possibility for the developer to check the appearance of the application and its interaction with the device in real conditions. In addition, it is possible to simulate the application with various hardware and various versions of iOS. • Beta testing: After building the prototype of the application, several users can be invited to give their opinions and feedback to the developer while using it. This is done using the TestFlight option available in the App Store. Now is a good time to check things like Notification and save data and network with someone else. The beta version of the application should be loaded and using iTunes, the name and email of the tester should be added. This person must install the TestFlight option to interact with the app and provide feedback. • Clouding test: It is very important to check the application and its performance on the real device. Because different devices benefit from different versions of the operating system and various changes. Therefore, performing such tests allows the developer to know more precisely how users of different devices will interact with the application. Next, by doing the Cloud test, you can find out how the application accesses and its connection with the Cloud section. At this stage, manual or automatic testing will be done to determine the quality of the application. • Development (Deployment): After building, installing and conducting tests, including beta testing, the application can be developed on the App Store. At this point, you need to connect to the Apple Developer Program. As a member of the program, one can access beta software, advanced app capabilities, extensive beta testing tools, and app analytics. Top programming languages in mobile application design Android application design Java: It is considered one of the best programming languages. The Android operating system is written based on the same language. This is why Google supports Android the most. Since this language is considered the best for learning mobile application development, its programs can be run on Android platforms. Python: an advanced and popular language that is used for scientific data and is far from any complexity. For more information, click on the website design link with Python. Basic: In other words, it is the best programming language in the field of Android application design, whose simplicity is its most important feature. Corona: this language, while being simple, has good control power and coding with it is easier than Java in some cases. Kotlin (Kotlin): This language somehow covered the weak points of Java and reduced the duration of processes that were executed with Java in a long time. PhoneGap: Using this language, it will be possible to design mobile applications without knowing other Android languages. Although this language works like the web, it will create an Android application as a result. iOS application design Swift: This programming language was produced and introduced about 7 years ago, which has experienced several updates in the meantime. The important thing is that Google wants to use Swift language instead of Java. This will not be good news for Java. C# (C#): This program from Microsoft has several patterns and is used in website design as well as iOS application design. PHP: This program was written about 26 years ago and uses open source code. Although it was first used for designing websites, now it is also used in the field of mobile applications for Android and iOS. C Plus Plus (C++): This program is derived from the C language and is almost similar to it. Using it, you can make a mobile application, and various applications are considered among its other features. Besides, it is more complete than the C language. HTML5: This programming language is the fifth version of HTML and has various uses. You can design a mobile application using a combination of Java and CSS. HTML5 can run on all devices. Java Script: This language is used to design web pages. It can also be used to create a mobile application through different platforms. If an application is built using JavaScript, it will no longer need separate coding. Multi-patterning is another feature of JavaScript. Online application builders and application development without coding Creating an application without coding is very popular today and has equipped non-professional users to create practical apps. In a situation where the use of smartphones is increasing, with the help of application design with app builders, you can create your own application without the need for coding and programming knowledge. This method is faster and at the same time more economical than other methods of making apps. Online application builders provide you with design, feature selection, application content creation, and configuration. These applications have made some tedious processes such as entering information easy, so that you can quickly prepare the application for publication. Also, if you don't have a major in app design, you will create an app with special features and at the same time stylish by having the ready templates of app builders at your disposal. Disadvantages of online application builders Application builders using ready-made frameworks. They convert your hybrid website into an application and provide it to you in less than a few minutes. Naturally, an application that is designed in less than a few minutes is not something that can help your business. If your goal is just to have an application, surely these application builders will be very useful for you, because with very little cost and time, you can have a version of your website application and publish it in different stores. But expect a lot from You should not have the functionality and facilities of these applications. But if your business is based on a professional idea and plan, and you intend to use the application to help the development of this process, application makers will definitely not be a good option for this. You can conquer new markets by having an application. Increase your income several times in this area, so it is better to choose a suitable platform for this work