Note 6 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021				2020
Risk-free interest rate		0.84%		0.26%		0.46%	-	0.92%		0.26%	-	0.33%
Dividend yield		0%		0%			0%				0%
Expected term (in years)		5		5%			5				5
Expected volatility		46.8%		69.6%		47.1%	-	92.6%		65.8%	-	69.6%

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
Options expired		-			-
Options forfeited		-			-
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
Options forfeited		-			-
Outstanding at June 30, 2021		1,262,500		$	0.86
Options granted		30,000			2.80
Options exercised		(65,000	)		0.18
Options expired		-			-
Options forfeited		-			-
Outstanding at September 30, 2021		1,227,500		$	0.94	5 years, 1 month	$	2,450,068
Exercisable at September 30, 2021		930,000		$	0.44	4 years, 5 months	$	2,326,943
Outstanding at December 31, 2019		1,349,000		$	0.23
Options granted		-			-
Options exercised		-			-
Options expired		(129,000	)		0.17
Options forfeited		-			-
Outstanding at March 31, 2020		1,220,000			0.24
Options granted		10,000			0.15
Options exercised		-			-
Options expired		(10,000	)		0.19
Options forfeited		-			-
Outstanding at June 30, 2020		1,220,000			0.24
Options granted		210,000			0.66
Options exercised		-			-
Options expired		-			-
Options forfeited		-			-
Outstanding at September 30, 2020		1,430,000		$	0.30	4 years, 5 months	$	487,773
Exercisable at September 30, 2020		1,208,500		$	0.24	3 years, 5 months	$	482,268

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		$	0.81
Granted		30,000			1.15
Vested		(215,000	)		0.41
Forfeited		-			-
Nonvested at September 30, 2021		297,500		$	1.13
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
Granted		210,000			0.37
Vested		(1,500	)		0.12
Forfeited		-			-
Nonvested at September 30, 2020		221,500		$	0.36