From Splash Colors:
VectorView allows you open and view CorelDRAW files on iPhone and iPad. To open cdr files, click Copy to CDRViewer from any app like Mail, WhatsApp, Telegram, WeChat or just send cdr files from your Mac through AirDrop, CDRViewer automatically detects your cdr file and opens it. CDR file format stands for CorelDRAW and this extension is proprietary format used by CorelDRAW software. CDR format is not recognized by other image editing programs and to save to other image formats it needs to be opened in CorelDRAW and then exported in other format. This can be done only on Windows. With CDRViewer there is no need to another operating system and another machine or another software to display and save CDR file formats.