Note 13 - Employee Equity Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of options			Weighted average exercise price (per share)		Weighted average remaining contractual term (in years)		Aggregate intrinsic value
Outstanding at December 31, 2016		1,225,000		$	0.17		2.62	$	83,425
Granted		4,650,000			0.26
Exercised		(300,000	)		0.13
Forfeited/cancelled/expired		(300,000	)		0.14
Outstanding at December 31, 2017		5,275,000			0.26		4.09	$	130,475
Granted		570,000			0.28
Exercised		(300,000	)		0.21
Forfeited/cancelled/expired		(2,975,000	)		0.25
Outstanding at December 31, 2018		2,570,000		$	0.28		3.47	$	16,675
Vested and exercisable at December 31, 2018		887,500		$	0.25		2.92	$	14,425

Share-based Compensation Arrangements by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding [Table Text Block]

Fair value of options vesting for the year ended	Number of options vested		Fair value of options vested
December 31, 2018		812,500	$	179,978
December 31, 2017		62,500	$	12,742

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

Awards breakdown by price range at December 31, 2018
			Outstanding						Vested
Strike price range ($)			Outstanding stock options		Weighted average remaining contractual life		Weighted average outstanding strike price		Vested stock options		Weighted average remaining vested contractual life		Weighted average vested strike price
0.00	to	0.20		150,000		0.93	$	0.17		150,000		0.93	$	0.17
0.21	to	0.30		1,695,000		3.54		0.26		550,000		3.15		0.25
0.31	to	0.50		725,000		3.82		0.34		187,500		3.82		0.34
0.00	to	0.50		2,570,000		3.47	$	0.28		887,500		2.92	$	0.25

Awards breakdown by price range at December 31, 2017
			Outstanding						Vested
Strike price range ($)			Outstanding stock options		Weighted average remaining contractual life		Weighted average outstanding strike price		Vested stock options		Weighted average remaining vested contractual life		Weighted average vested strike price
0.00	to	0.20		300,000		1.93	$	0.18		250,000		1.48	$	0.17
0.21	to	0.30		4,250,000		4.12		0.25		150,000		1.30		0.22
0.31	to	0.50		725,000		4.82		0.34		-0-		0.00		0.00
0.00	to	0.50		5,275,000		4.09	$	0.26		400,000		1.42	$	0.19

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

	Stock option assumptions for the period ended
Stock option assumptions	December 31, 2018		December 31, 2017
Risk-free interest rate		2.91%		1.81%
Expected dividend yield		0.0%		0.0%
Expected volatility		111.0%		127.1%
Expected life of options (in years)		5		5

Share-based Compensation, Activity [Table Text Block]

	Weighted average grant date fair value
	for the year ended December 31,
	2018		2017
Stock options granted during the period	$	0.23	$	0.21
Stock options vested during the period	$	0.22	$	0.20
Stock options forfeited during the period	$	0.19	$	0.13

Schedule of Nonvested Share Activity [Table Text Block]

	Shares underlying stock options		Weighted average grant date fair value
Nonvested shares at January 1, 2018		4,875,000	$	0.21
Nonvested shares at December 31, 2018		1,682,500	$	0.24