Yes, you can choose which devices to show your optin forms on (Desktop, Tablets or Mobile). You can modify this setting any time. Follow the easy steps mentioned below.
Step 1: Click on ACTIONS on the form that you wish to disable for mobile users. Select the Edit option from the drop-down menu.
Step 2: Go to the Behavior step.
Step 3: Expand the Display Rules panel, and select the devices of your choice. Disable or switch off the MOBILE DEVICES toggle.