Note 2 - Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Prepaid subscriptions	$ 383	$ 29
Prepaid insurance	60	314
Prepaid marketing and sponsorships	60	60
Other	260	267
Total prepaid expenses and other current assets	$ 763	$ 670