PDF preview in Apollo
Uploading files is one of the central features in Apollo. Knowing that you need to design a leaflet with set prerequisites is great. However, at some point you will need to show that leaflet to the customer, and will most likely attach it to a comment, asking for input.
One aspect of file upload is that you expect to see a preview of the file you are downloading before actually transferring the whole thing onto your computer (similarly, most desktop file managers will show images' thumbnails when you open up a folder).