It depends on the size, type and function of the app.
Larger apps built for the App and Android Store can be costly. However there benefits will outway the cost.
Web apps can be a cost effective option for internal operational functions. These function like an app but run from a webpage.
Basic (non bespoke) apps can be done for a monthly fee, ongoing while you use the apps.
We like to pride ourselves on giving the best solutions for our clients problems. Please contact us and we can arrange a quote.