Annual report pursuant to Section 13 and 15(d)

Note 11 - Stock Options and Warrants - Stock Option Activity (Details)

v3.21.1
Note 11 - Stock Options and Warrants - Stock Option Activity (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Outstanding, shares (in shares) 1,349,000 1,376,500
Outstanding, weighted average exercise price (in dollars per share) $ 0.23 $ 0.23
Options granted, shares (in shares) 235,000 3,000
Options granted, weighted average exercise price (in dollars per share) $ 0.64 $ 0.21
Options exercised, shares (in shares) (50,000) (10,000)
Options exercised, weighted average exercise price (in dollars per share) $ 0.20 $ 0.10
Options expired (in shares) (99,000) (15,500)
Options expired, weighted average exercise price (in dollars per share) $ 0.18 $ 0.10
Options forfeited, shares (in shares) (40,000) (5,000)
Options forfeited, weighted average exercise price (in dollars per share) $ 0.16 $ 0.46
Outstanding, weighted average remaining contractual term (Year) 4 years 153 days 3 years 335 days
Outstanding, aggregate intrinsic value $ 1,591,223
Outstanding, shares (in shares) 1,395,000 1,349,000
Outstanding, weighted average exercise price (in dollars per share) $ 0.31 $ 0.23
Exercisable, shares (in shares) 1,160,000 1,325,500
Exercisable, weighted average exercise price (in dollars per share) $ 0.24 $ 0.23
Exercisable, weighted average remaining contractual term (Year) 3 years 120 days 3 years 302 days
Exercisable, aggregate intrinsic value $ 1,400,423