You can let a client complete a form on your device by choosing the "Fill in" option from the dot menu on the relevant form.
After clicking "Fill in", find the client and choose the "Open in new tab" option.
Note: you could potentially expose sensitive client information by handing over your device to a client. To make things safer, you'll be prompted to log out of Bookem first. This way they won't have access to your data on Bookem. Make sure your bookem password isn't saved in your browser if you do this.