For customers, contacts & prospects: need a field to hold a moble phone number

We do use the fax number field so that is not an option.  Currently, we are putting the cell numbers in the country field, since we do not use that one.

I'll request this be added to Apex 2017. In the short term - do you use the Fax phone field? You could go into Screen Designer and change the Fax name to read Cell. It isn't the best solution but that field might be reused if you never fill in fax number or use it.