App development

Hi I have a requirement for an app for both ios and android tablets. The app will be used to test operatives knowledge following training courses. It will need to contain various test pages for different aspects of the construction and industrial sector . The trainer will test the operator using a number of questions made up of multiple choice options and free text answers. Each test page must not move forward until all questions have been answered by the operator and once the page is completed cannot move back. Once the test is completed the Trainer will need to be able to save the file in order to email back to the training providers office from the app straight away or when there is an internet connection available. The candidate must be able to sign and date the test paper and the completed test paper should be secure and read only when emailed so cannot be tampered with at a later date. The total number of categories is about 150 so a search facility would be helpful when opening the app, the number of categories to be developed and included in the first instance would be dependent on cost. Since the intended recipients of this app would be Training Providers, not the general public, a security code to access the app would be required or some form of code as the test papers contained in the app would be confidential