The app needs a redesign with a more modern ui/ux that is much nicer to use and doesn't look so old, I'm a programmer and I understand that this task is monumental, but sooner or later it has to be done, in 5 years the app won't it should look the same as it does now, you should constantly improve your design and user experience, what I recommend is to hire a team of very talented ui/ux designers to carry out this task, together with frontend developers trained to execute the new redesign of the app, I am sure that a radical change in the design of the app will cause great joy in the clients since it will be much more pleasant to use, I recommend hiring a world-class designer like Malewicz, I am sure that this will contribute a lot to the perception of value that people who use the application have