You can manage all your submission from your Boom Form's Dashboard and export them to a CSV/XLS spreadsheet or Text document.
You can export the submissions as follows:
Go to your Weebly Editor.
Move to the page where you have the form.
Click on Form.
Go to the Dashboard tab.
When the Dashboard opens, click on the All Entries button.
Select your form and the time period from the corresponding dropdowns.
Select the format you want to export to (CSV/ Excel/ Text) and click on Go.