It would be great if a user could save a submission on mobile and continue on the Windows Desktop client. This is most commonly requested by customers who perform Audits. Typically they'll go on-site to note the initial subject areas of the audit, jotting down the outline of the audit on a mobile device with the intention to fill in the details later. Due to the immense write-ups required for a lot of these audit subjects, it's easiest to save the form after inputting the preliminary info on mobile and resume it on a computer so that they can type out the details.
Currently, the only workaround is to have them create an optional "workflow to mobile" which disables the ability to use the table of contents. Due to audits requiring lots of loop screens and screens in general, the table of contents is essential.