Quarterly report pursuant to Section 13 or 15(d)

Note 9 - Stockholders' Equity - Summary of Option Activity for Employees and Non-employees (Details)

v3.21.2
Note 9 - Stockholders' Equity - Summary of Option Activity for Employees and Non-employees (Details) - Share-based Payment Arrangement, Option [Member] - USD ($)
3 Months Ended 6 Months Ended 12 Months Ended
Mar. 31, 2021
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Share-based Payment Arrangement, Nonemployee [Member]          
Number of options (in shares) 74,997 74,997 49,998 49,998  
Weighted average exercise price, outstanding (in dollars per share) $ 1.41 $ 1.41 $ 1.87 $ 1.87  
Weighted average remaining contractual life, outstanding (Year)   2 years 10 months 13 days 2 years 11 months 8 days 3 years 2 months 4 days 2 years 11 months 8 days
Aggregate intrinsic value, outstanding $ 77,664     $ 54,748 $ 0
Number of options granted (in shares)   16,666 8,333    
Weighted average exercise price, granted (in dollars per share)   $ 4.30 $ 1.65    
Number of options exercised (in shares)   0 0    
Weighted average exercise price, exercised (in dollars per share)   $ 0 $ 0    
Number of options exercisable (in shares)   52,769 41,663    
Weighted average exercise price, exercisable (in dollars per share)   $ 1.68 $ 1.71    
Weighted average remaining contractual life, exercisable (Year)   2 years 1 month 13 days 2 years 10 days    
Aggregate intrinsic value, exercisable $ 50,658   $ 84,579    
Common stock issued to employee for stock options exercised (in shares)   0 0    
Number of options (in shares)   91,663 58,331 74,997 49,998
Weighted average exercise price, outstanding (in dollars per share)   $ 1.69 $ 1.87 $ 1.41 $ 1.87
Share-based Payment Arrangement, Employee [Member]          
Number of options (in shares) 1,953,443 1,953,443 1,212,442 1,212,442  
Weighted average exercise price, outstanding (in dollars per share) $ 1.88 $ 1.88 $ 1.71 $ 1.71  
Weighted average remaining contractual life, outstanding (Year)   7 years 2 years 4 months 24 days 3 years 1 month 2 days 2 years 4 months 24 days
Aggregate intrinsic value, outstanding   $ 188,018 $ 0 $ 476,964 $ 0
Number of options granted (in shares)   2,032,175 0    
Weighted average exercise price, granted (in dollars per share)   $ 2.48 $ 0    
Number of options exercised (in shares)   (435,558) 0    
Weighted average exercise price, exercised (in dollars per share)   $ 1.58 $ 0    
Number of options forfeited and expired (in shares)   0      
Weighted average exercise price, forfeited or expired (in dollars per share)   $ 0      
Number of options exercisable (in shares)   745,092 1,117,829    
Weighted average exercise price, exercisable (in dollars per share)   $ 1.93 $ 1.84    
Weighted average remaining contractual life, exercisable (Year)   2 years 4 months 28 days 1 year 10 months 2 days    
Aggregate intrinsic value, exercisable   $ 124,701 $ 0    
Common stock issued to employee for stock options exercised (in shares)   435,558 (0)    
Number of options (in shares)   3,550,060 1,212,442 1,953,443 1,212,442
Weighted average exercise price, outstanding (in dollars per share)   $ 2.26 $ 1.71 $ 1.88 $ 1.71