I am sharing few tips which will help you to find out a good developer for your app.
Share about your project in your connections, you can discuss your need with your friends, colleagues, and family members and also ask them to give references if they have any. Here don’t get confused with the long list of the developer, approach them as soon as you get their contact number.
Self-research- search for developers on flatforms like LinkedIn and other social media spots. Put an explanatory post on your LinkedIn wall with proper hashtags. You will definitely receive feedback on your post. List those people for further contact.

Narrow down your list

Quality first
Opt for a good company
It is always cheaper to hire a freelancer than a company, but you should make sure that your project must have a backup team. Development needs continuity and must meet the deadlines. In that case, hiring a good company is always the best option.
It is only a company that can offer the kind of continuity you need. The chances of an individual after 6 months are not so good. He could have relocated or changed his business.
Go for the complete package- developing an app is not only a solution you are looking for, but the product must also be tested at different levels before launching it for customers. The development also needs effective suggestions and solutions for a team, that you can only find with a company.