How to talk app: The A-Z of mobile development


10 minute read
Tom Melamed

Tom Melamed

Non-executive Director

Digital Insights

Mobile Technology

How to talk app: The A-Z of mobile development

Back in 2014 we published our first guide to app terminology. Progress marches on and the jungle of jargon grows ever more dense. Time then, for an updated A-Z of apps.

AI (Artificial Intelligence)

The intelligent behaviour exhibited by computer programs, e.g. the conversations you can have with assistant apps like Siri or Cortana.


A mobile operating system created by Google. Android runs on 1.4 billion devices around the world.

API (Application Programming Interface)

A system provided by an online service or website (for example, Google Maps or Flickr) which allows apps to use the website’s data or services (for example, embedding a Flickr image in an app, or having the app automatically upload an image to Flickr.)


Short for ‘application’. A piece of software that performs a task. A game is an app, as is an email reader.

AR (Augmented Reality)

AR (Augmented Reality) is technology that adds content to a virtual representation of the real world. For example, when a user views a chosen landmark through the viewfinder of their smartphone camera, a VR app would overlay graphics, sounds or other content to the image. For examples of AR in action, read our blog on AR for heritage sites.

ASO (App-Store Optimisation)

A set of techniques for making an app more visible for searchers on webstores including Apple’s AppStore (for iOS apps) or Google Play (for Android apps).


The back-end includes the bits of an app or service that sit in the cloud, which users don’t directly see or interact with. For example, the server that stores the photos on Instagram is part of the back-end, while the app interface that you actually use on your phone is part of the front-end.


A way of wirelessly connecting your device to accessories like speakers, keyboards, and wireless headphones.

Bluetooth 4.0,

Also known as Bluetooth Low Energy or Bluetooth Smart, this is a specific version of Bluetooth which lets multiple devices talk to the same Internet-capable smartphone or computer through small pulses of data. It’s easier to set up than previous versions of Bluetooth and uses less energy, which makes it more attractive to hardware designers and software developers. Read about how we’ve used Bluetooth 4.0 here.


A specific version of an app made by developers. Every time code is turned into a working app, this constitutes a new build. Some builds may be developed for release but most are used internally for testing.


A set of instructions that tells computer hardware what to do.


The act of writing code.

Cross-platform apps

Apps which can be used on different devices with different operating systems. Cross-platform apps are often cheaper to develop than Native Apps, but sometimes at a cost of not feeling quite as smooth or fitting as well with the normal interface of the device.

Delivery day

The day the app is delivered to the app stores, but not necessarily the day the app is available to users. Both Apple and Google review all apps before releasing them for download.


A stage in the process of creating an app. The design stage begins after deciding on the purpose of the app and the specifications (what sort of devices you want it to run on, what operating systems you want it to run in). The design stage is the stage at which the basic functions and structure of the app are laid out.


Hardware objects which we use for computing. Your smartphone is a device, your Kindle is a device, your FitBit and satnav are devices.


Both an action and a metric for an app’s success. To use an app, users have to download it and install it on their device (with the exception of Instant Apps – see below). The number of downloads is a metric for the success of an app – more downloads means more people who might be using it.


A set of instructions programmed on a hardware device or component. It tells the device or component how to communicate with other hardware devices or components, and how to run. For simple devices without operating systems (like Fitbits or cordless phones) the firmware is all the software that runs on the device. For more sophisticated technology, including smartphones, firmware is restricted to the very simplest instructions – telling the hardware how to do things like find and load the operating system.

Front-end apps

Apps with which users directly interact. Web browsers, games and email readers are all front-end apps.


Using the networks and other signals to which your device is connected to find you in the real world. These can include GPS, wi-fi and mobile data networks.


Geotags associate a photo, video, or social media post with a real-world location. If you take a photo of yourself at a restaurant, upload it to Facebook, and Check In to show where you are, you are creating a geotag.

GPS (Global Positioning System)

GPS uses satellites in space to provide locational information to your devices, enabling them to understand where you are on earth. GPS is how SatNavs know where you’re starting from and how far along your journey you are. We use this technology for our AppTrails service.


Physical technological things. A device is hardware – so are all the bits of the device which work together, like a smartphone’s screen and speaker and camera.

HTML (Hyper Text Markup Language)

A kind of code used to create web pages.

Hybrid apps

A hybrid app can work on multiple operating systems while a native app is restricted to the operating system for which it was designed. Find out more about native and hybrid apps here.


A protocol created by Apple, which uses Bluetooth 4.0 to emit a signal. Other devices pick up that signal and respond to it. Find out how we use iBeacons here.

Instant Apps

A new Android service. Instant Apps enables users to run Android apps instantly, having downloaded them via a link in a browser window. Unlike conventional apps, Instant Apps are installed without requiring the user to visit the Google Play store or enter a password.


The operating system for mobile devices manufactured by Apple. Apple has sold over a billion iOS devices.


A programming language used to create interactive websites and some apps.

Mobile devices

Devices which you can use on the go, unlike desktop or laptop computers which you have to stop, sit down and stay in one place to use.


A programming language which Apple use for their iOS and OSX operating systems – now slowly being replaced by the programming language Swift.


Not currently connected to the Internet.


Currently connected to the Internet.

Operating Systems

The programs which make your phone or tablet work. The operating system controls what the device displays on its screen, what sounds it makes, how it connects to the Internet or other devices and what it does when you touch, tap or click something.


The operating system used for Apple Macintosh computers.


A set of rules and instructions for computers to communicate with each other over local networks, the Internet, or Bluetooth connections.

Native apps

Apps created specifically for one mobile operating system, using that system’s programming language. They tend to be quicker and feel more fluid to use than hybrid apps – but they will only work on a finite range of devices. Find out more about native and hybrid apps here.

NDA (Non-Disclosure Agreement)

Clients, developers and testers sometimes sign NDAs to secure ideas, builds and insights for the app they are creating. Strict penalties apply to anyone who breaks the NDA by discussing the app with anyone who has not signed it.


A web scripting language – a kind of code which can be inserted into the HTML that generates web pages. This code runs on the server before the web page is presented to the user. PHP is normally used to create interactive and dynamic content for websites.

Programming languages

Used to write code. Some languages are associated with specific devices; others work on any device.

Publishing Processes

The things you have to do to make your app available to the general public. Android and iOS have different publishing processes.

Push Notifications

Also known as push messages, these are sent by an app or a back-end connected to an app – they pop up like text messages and contain information about the app. When your calendar app sends a reminder that you have a party to go to, it is sending you a push notification. Find out how we use push messages here.

QA (Quality Assurance)

The process of testing and fixing, by which problems with an app are identified before the app is released to the general public.

React Native

A new development platform for apps, recently created by Facebook. Importantly, React Native works on both Android and iOS devices. This means developers can write most of an app once and still have it work and feel native on both operating systems. Find out more about the implications of React Native, and our plans to make the most of it, here


A general term that describes computer programs. Software can be difficult to describe because it is “virtual” – unlike hardware, you can’t hold it in your hand. Software consists of lines of code, written by computer programmers, that tell the hardware to do particular things.


A programming language created by Apple and used for coding iOS apps.

UX (User Experience)

Basically, “what it feels like to use an app or device”. Apps which make it too easy to tap the wrong thing, websites which display tiny text on a mobile device, or devices with tiny buttons are all delivering a poor user experience.

UI (User Interface)

The user interface is what you use to control a device. It can refer to software, hardware or both: the arrangement of icons that appear on your smartphone’s screen, the actual physical touchscreen itself, or both.

VR (Virtual Reality)

Virtual reality is an environment which is totally simulated by a computer, which can be explored by sight, sound or – more rarely – touch.

Web Apps

Apps which you use in a web browser like Internet Explorer, Firefox or Chrome. They work on multiple platforms and don’t have to be installed on your device, but they can be slow and only work online.


Components of a UI. They enable a user to perform a function or access a service. The row of buttons on a web page which let you share the page or follow the author on social media are widgets. Give ours a try – follow us on Twitter or LinkedIn.

OK: we didn’t quite make it to Z. Nonetheless, you’re bound to hear many of these 48 technical terms from your developer. If you found this post useful, check out our handy guide to copyright in apps and outsourcing your development.

Calvium build beautiful, intelligent apps for forward-thinking brands. Working closely with heritage, engineering and agency groups, we provide award-winning app development that drives customer engagement and boosts innovation in business.

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