Most websites are now "responsive" websites. That is, the sites are equally usable no matter on which device you view them. You can view them whether you have a phone, a tablet, or a full sized monitor.
Have you noticed that on Safari on iphone or ipad, you can click the options icon and choose "Add to Home Screen"? On Android, you can do the same thing with the Chrome browser clicking on the three little vertical dots. Once the web page is saved to your home screen, you can click the icon and open the page as a stand-alone page. Very convenient. This works for any web page.
However, the future is "progressive web apps" or PWAs.Read More.
These are responsive web pages that go a step further and can act like a native iphone, ipad, or android app. A PWA can cache the page, so that you can open it when you are offline - unless of course the app will need data that it can't store on your device. A PWA can make phone calls, take a photo, display a notification, detect vibrations, get battery status, and many other features, depending on the device. In fact, the need for expensive native apps for portable devices is rapidly diminishing.
Advantages of PWAs
With a PWA. a web developer can write an app using a skill set they already have, instead of learning new languages. Also, the same PWA will work on all devices. You don't have to write one version for iphones and another version for android phones, for example.
A big advantage is that a PWA does not have to be accessed from an app store. Keeping an app on the Apple app store costs $99 per year and must go through a long approval process to be there. The Google Play store and the Windows apps platform have much lower fees, but still require a process to get in those stores. If the app makes money, you will owe the app store around 30%. With a PWA, your users can bypass the app store and just visit your website to click " Add to Home Screen" and you pay no fees. Since users are habituated to finding their apps on the app store, you can also choose to publish your app on an app store.
For demonstration, I created a simple PWA to convert Fahrenheit to Celsius and vice versa. You can get it at: todaydata.com/converter.
As more and more browsers step up support for PWAs, it will become easier and cheaper for everyone to create apps just for their clients and employees or for everyone.