Yes, you can customize the order your customers book their staff, venue and time. You can even choose to randomly assign an staff member or location. This allows customers to skip these steps and go right to just picking a time.
You can find these options in Appointment Settings, available under Settings > Appointment Settings. (These are your "umbrella" settings that apply to all your appointment boards. You can also control these settings from individual boards.)
Here's an example of how you could set up your appointment scheduling to require customers to only have to pick a time and a place (skipping the staff selection part).
To make this change for just a specific board, click Appointments > Boards > edit the board > scroll to Checkout flow order.
Will these changes be implemented in the mobile app, and on the Appointments plugin I'm using on my site?
Yes, they'll show on both.
The quickest way though to quickly check what you're customers are seeing though is to preview from your own dashboard. Click Appointments > Schedule > select the board in question > click Checkout. (This is the customer checkout page).
And from your dashboard, the plugin version is easily previewed by clicking Studio Setup > Add to Website > Appointments.
To preview the customer app > create a test customer from your Momence dashboard > confirm your account by email > download the Momence app from the app store > login to the app > select your studio > tap Appointments.