If they have an office in Mumbai then it’s good as it will help in better communication. After that, look for the following factors:
Yes, there are many free platforms like Google Appsheet that enable you to do so, but they provide very basic functionalities.
There are many reputed companies in Mumbai. We have provided a list of top verified developers in Mumbai.
App development in Mumbai starts from 2.5 lakhs and can go over 15 lakhs depending on the complexity of the app and features added.
Yes, there are many apps that generate millions of dollars each year.