Note 6 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months Ended			Three Months Ended			Six Months Ended			Six Months Ended
	June 30, 2021			June 30, 2020			June 30, 2021			June 30, 2020
Risk-free interest rate	0.77%	-	0.87%		0.33%		0.46%	-	0.92%		0.33%
Dividend yield		0%			0%			0%			0%
Expected term (in years)		5			5			5			5
Expected volatility	47.1%	-	47.7%	65.8%	-	66.0%	47.1%	-	92.6%	65.8%	-	66.0%

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options outstanding
				Weighted average		Weighted average	Aggregate
				exercise price		remaining	intrinsic
Incentive Options	Shares			per share		contractual term	value
Outstanding at December 31, 2020		1,395,000		$	0.31
Options granted		145,000			2.62
Options exercised		(25,000	)		0.14
Outstanding at March 31, 2021		1,515,000		$	0.53
Options granted		127,500			2.85
Options exercised		(360,000	)		0.22
Options expired		(20,000	)		0.17
Outstanding at June 30, 2021		1,262,500		$	0.86	6 years	$	2,876,868
Exercisable at June 30, 2021		780,000		$	0.33	3 years, 2 months	$	2,194,843
Outstanding at December 31, 2019		1,349,000		$	0.23
Options expired		(129,000	)		0.17
Outstanding at March 31, 2020		1,220,000			0.24
Options granted		10,000			0.15
Options expired		(10,000	)		0.19
Outstanding at June 30, 2020		1,220,000		$	0.24	3 years, 9 months	$	37,353
Exercisable at June 30, 2020		1,207,000		$	0.24	3 years, 8 months	$	36,703

Schedule of Nonvested Share Activity [Table Text Block]

	Nonvested
				Weighted average
				grant date
	Shares			fair value
Nonvested at December 31, 2020		235,000		$	0.36
Granted		145,000			1.22
Vested		-			-
Forfeited		-			-
Nonvested at March 31, 2021		380,000		$	0.94
Granted		127,500			1.19
Vested		(25,000	)		1.01
Forfeited		-			-
Nonvested at June 30, 2021		482,500		$	0.94
Nonvested at December 31, 2019		23,500		$	0.17
Granted		-			-
Vested		(5,000	)		0.21
Forfeited		-			-
Nonvested at March 31, 2020		18,500		$	0.15
Granted		10,000			0.08
Vested		(15,500	)		0.16
Forfeited		-			-
Nonvested at June 30, 2020		13,000		$	0.09