Experienced UI/UX designer needed

Hi there

We are looking for an experienced UI/UX designer to initially review our web app and provide feedback, briefly advise on what can be improved etc (1-2 hours). If we like your advise we may ask you to put your recommendations into reality, i.e. provide a mockup with your improvements.

Other than this, we'll need to introduce themes (colour schemes) but this might be a separate job.

Please bid a fixed price for the initial job for now, i.e. check and provide feedback.

UK and US based preferred but will consider other countries only in case you have a great experience/portfolio/feedback.