Develop High fidelity mockups (UI/UX) designs for a mobile chat application

We need to develop a mobile chat application and need someone to develop high fidelity mockups . There will be around 10-12 pages including Login Page, Accounts, Group Chat, Private chat etc. Also will need icons for the app (around 100). Please provide links to existing works that you have done and based on that we will finalize. Also mention the timeline you can get this developed. Experience with Adobe Illustrator, Sketch, Figma, Photoshop is desirable.