Looking for an experienced designer to graphically design an app UI

General information for the app: The relevant information regarding the app will be made available once the job has been won.
Kind of development: New app from scratch
Description of every page/module: We are looking for an experienced designer to graphically design a UI for an app currently in development.

The relevant information regarding the app will be made available once the job has been won and once a NDA has been signed.

The designer should be able to show some examples of previous work, be experienced, and familiar with designing for both Android and iOS platforms. The designer should be able and willing to make many revisions until all other parties are happy and the app looks right. The designer should also be willing to look at other apps (which we will mention) and design work before stating to get a feel of what we want it to look like.

Note - Since this kind of work is ongoing, time consuming and lengthy the wage/payment will reflect this and will be negotiated.
Description of requirements/features: Initially, what needs doing
- App UI
- App logo
Extra notes: