Add an attachment
You can add one or more attachments to a task (document, photo, PDF…). Access the detail panel of the task in question by clicking on it.
Task > What tab: click on the “Add an attachment” button and select your document:
After being uploaded, the attachment will appear at the bottom of the task details panel:
In the What view, when a task contains an attachment, an 
icon is displayed:
Note1: An attachment can not exceed 100 MB, but you can add as many attachments as you want.
Note 2: The addition of attachments is reserved for users with a subscription. However, users with a Free count can download attachments.
Preview an attachment
Click on the menu button at the bottom right in the task details:
In the attachment menu, click on the attachment title:
The document preview is displayed on the screen:
Note 3: only some document formats allow previewing:
bmp image/bmp ✓
htm text/htm ✓
html text/html ✓
jpg image/jpg ✓
jpeg image/jpeg ✓
pdf application/pdf ✓
png image/png ✓
tiff image/tiff ✓
txt text/plain ✓