In earlier days mobile applications were inexplicably associated with public stunts, flukes or accessories, take for example that – ‘ I’m rich’ app That came for $99,999when app store had just opened. Well now we can see that the world’s passed that. The apps today have numerous features and are rapidly expanding – take anything- Gmail, whatsapp or even uber, and as you add more features the cost of the app development becomes even steeper. 
Simple adjustments like the adaptations to screen size will increase you budget considerably; this is as the U.I. which adjusts the size of the application to be proportional to the screen size which adds to your budget. In fact you should be ready to size up your budget by 1.5 times its original size. It is only wise to introduce tablet U.I. when your app is very popular and you have a firm foothold on every major social media platform there is. One fact imperative to know is that majority of app features only work in portrait mode.
Another fact is that in 2018 your app should only support latest version of IOS and android versions. Another fact of utmost importance is that your budget will increase 2 times its original size if it works on old devices. If you device is 
to work offline matters become even more complicated. You app must operate on a series of algorithms and this will increase you budget by $8000 to $12000. If you want to add push notifications- take for example notifications, it will take from around $1,500 to $2,500 for basic push notifications.
To have your app link to social media to get it to store data, personalize experience andstore preference etc. then. If you want this in your app then be ready to add another $2,400 to your budget. To localize your app to suite its location you would need to add $500 to your budget. This was a basic summarization of what all you would want to add in your app and how much does it cost to create an app. We hope that using this as a basic guide you can define the structure of your app and its components along with creating a structural and affordable budget.