You can export your content from Evernote into Boost Note one doc or all at once, here's how:
Exporting individual Evernote doc into Boost Note
In Evernote, select the doc you wish to export and click "Export Notes..."
Export file as HTML
Upload files in the Boost Note
Exporting Evernote docs in bulk into Boost Note
Click on 'Notebooks' to enter the notebook view
Select File > Export all Notes...
Export as html
Upload files in the Boost Note