This following description is of the app in it's current design. You are free to be creative!
Mainpage: This is where the user can create a new timeline or open an existing timeline. All the existing timelines are shown in a grid. The title of the timeline can be long (max two lines). There should be a properties button where you can set timeline properties such as name, image, start date, end date, and timeformat.
Timeline: This page shows all the events relative to each other in time. On the bottom there is an time axis with time labels. The user can pan and zoom the timeline. If the delete button is pressed it activates delete mode and all the events starts shaking (just like when deleting apps on an iPad). If the user clicks on the new event button (+) an event properties popup is shown where title and date can be added before the event is created. Remember that the title can be long (like book titles: "Harry Potter and the Half-Blood Prince" and "The Hundred-Year-Old Man Who Climbed Out of the Window and Disappeared")
Event view: This page lets the user add text, pictures and videos to the event. All the elements can be scaled, stretched and rotated. the inspiration for the controls has been Apples Pages app. There is also a properties button. It no element is selected the properties button open the even properties. It a text is selected the text properties are shown where the user can select font, text color, bold, italic and underlined.
In the future where will be support for sending timelines to other users, exporting the timeline to various formats, etc.
The final design should be delivered in either Sketch (preferred) or Photoshop format.