Greetings sir,
I have read your project description and I we'll need full written list of requests you might have here. There is also question of UI designs, something specific you had in mind or something you'd like us to design.
Do bare in mind that time frame might variate based on complexity of your request.
Free demos are our good practice, so we could offer a one. It would help you, in your review to help reassure you in quality of the product we offer.
As for our expertise, we are team of 10 European iOS / Android developers, all experienced in their field of work. Quality is our main goal, for the purpose of being team of choice for our employers should they need any IT work done again.
If you have any questions please do not hesitate to contact us.