Fillable Forms for Customers

I have made a "fillable" order form for our customers to use, however many of them accessing the form via their tablets and phones cannot fill out the form which makes the process difficult and frustrating. I have developed the order form with Acrobat Pro DC and have selected the "Reader Extended PDF" when saving, but customers still can't fill out the form (unless they are on an actual computer which many these days are not).

Is there any way I can re-jig or save this form in order for customers to view & fill in the form on their devices without having to download a specific Adobe program/software?