To create entries from your smartphone, you can scan your company's QR code (if displayed). You don't even need to download the app. Follow the step-by-step instructions to create an entry.
If you don't have a QR code to hand, you need to open the app (join your company if necessary) and navigate to the desired sub-item from the dashboard ("First aid book", "Near misses" or "Unsafe acts"). On Android, you can add an entry via the plus in the bottom right corner. On iOS, the plus button is at the top right.