@viktor your response 'Mobile app development cost' is
already 160% 'of the budget.' That's hilarious and telling.
It is a Sisyphean task to estimate software development
'costs' from the 'budget.' Beware.
For an excellent, apropos example, the original question was,
"How Much Does it Cost to Design an App?" Yet, you offered estimates for mobile development cost (?), not design. This is emblematic of many serious problems developing
software - answering a question that was never asked! It is a classic
Suggest you read 'the bible' of software engineering, The Mythical Man-Month. BTW, it's called the "bible" because"everybody quotes it, some people read it, and a few people go by it."
Finally, US Federal Govt has spent $2.1B (yes BILLION) for design and dev of the app for the failed 'Patient Protection and Affordable Care Act' (PPACA) aka Obamacare. It is a galaxy of govt software incompetence.
Because govt has an unlimited 'budget' (taxes) app design & dev costs are of NO concern whatsoever. For example, SalesForce.com offered the Administration to build and run the PPACA app for 5-years... for FREE. The offer was summarily rejected by smug govt apparatchiks that 'know better' and get rich in the process.
Again, beware of ever forecasting software design and development from the 'budget.' Rather, focus on creating and keeping customers.
While developing an app, the biggest question for any company is how much it would cost to develop the app. Companies would like to know how much would it cost for them to build the app from scratch.
While the question does seem simple, often, it is hard to predict the exact price until the project is finished. Approximations can be given but the app development process can be hindered by a number of factors, including emergence of better technologies and more app testing required than thought of initially. As an app entrepreneur, the only thing you can do is take a rough estimate of the cost depending the requirements of your app.
Read more here: How Much Does Your App Cost? Estimating App CostDevelopment
Good design probably costs a lot, and that is a pressing problem especially for startups and small businesses. They say here https://erminesoft.com/how-much-does-it-cost-to-design-an-app/ that it depends on location, and, I guess, quality. That is one more thing to keep in mind.
You need to define you App!