Hello,
My name is Nizar and I am representing a great team of highly qualified and talented Unity developers and designers. To estimate the price and time terms, we will need to see your source code condition. If everything is alright, it will take us 3 days and 100$, but if all plugins need to be replaced and there is a lot of bugs in the code, we will need up to 1 month (depends on the workload) and up to 800$.
If possible, provide me with the code of your app so I can estimate the exact price and time terms, thank you in advance.
Hope for hearing from you soon,
Yours sincerely,
Nizar K.