app modifications for existing app

I am looking to make modifications to an existing app and am in need of experienced freelancers to help me make the desired changes. The modification required is related to the bug fixing, and although I do have some ideas in mind, I am open to suggestions as well. The platforms that require modification are both iOS and Android. If you have the experience and knowledge to help me modify the app and give it a polished look and feel, please get in touch and let me know how you can help. I look forward to hearing from you!