Can I create a link between tasks in different subprojects?
At this moment you can only view an external task created with MS Project.
What are external tasks?
Tasks from different subprojects can be linked together, forming a predecessor/successor dependency. When you open one of the subprojects in application, all of the predecessor tasks from other subprojects will be shown next to the local tasks in the project being opened. They appear with different bar/box style and font in the different task views, e.g. in grey color, so they can be visually distinguished from the local tasks. These tasks are called External tasks.
Does the application allow to open Microsoft Project files that contain subprojects?
The application allows you to open Microsoft® Project files (mpp) that contain subprojects. If the opened project plan includes subprojects, a specific graphical indicator will be shown in the Indicators column. This indicator will tell that the task next to it is an inserted project (also called a subproject). The inserted project appears as a summary task in the master project. To upload subprojects, click on the plus sign (+) corresponding to each subproject and you will be asked to locate the subproject on your disk. Then the subproject will be instantly viewed.