Note 2 - Change in Accounting Principle - Cumulative Effect of Changes for Adoption of New Accounting Standard (Details) - USD ($)	3 Months Ended			9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019		Mar. 31, 2020	Mar. 31, 2019		Jun. 30, 2019
Paid in capital							$ 6,333,135
Retained earnings	$ 8,078,107			$ 8,078,107			8,701,942	[1]
Selling, general and administrative expenses	1,687,676	$ 1,540,348	[2]	4,938,983	$ 4,889,284	[2]
Income from operations	(97,900)	114,860	[2]	(637,665)	259,604	[2]
Net (loss) income	$ (97,373)	$ 137,880	[2],[3]	$ (623,835)	$ 282,599	[2],[3],[4]
Basic (in dollars per share)	$ (0.01)	$ 0.02	[2],[3]	$ (0.08)	$ 0.04	[2],[3]
Diluted (in dollars per share)	$ (0.01)	$ 0.02	[2],[3]	$ (0.08)	$ 0.04	[2],[3]
Stock-based compensation expense				$ 428,228	$ 383,425	[4]
Accounting Standards Update 2016-09 [Member] | Previously Reported [Member]
Paid in capital							6,186,393
Retained earnings							8,848,684
Selling, general and administrative expenses		$ 1,505,922			4,798,045
Income from operations		149,286			350,843
Net (loss) income		$ 172,306			$ 373,838
Basic (in dollars per share)		$ 0.02			$ 0.05
Diluted (in dollars per share)		$ 0.02			$ 0.05
Stock-based compensation expense					$ 292,186
Accounting Standards Update 2016-09 [Member] | Revision of Prior Period, Adjustment [Member]
Paid in capital							146,742
Retained earnings							$ (146,742)
Selling, general and administrative expenses		$ 34,426			91,239
Income from operations		(34,426)			(91,239)
Net (loss) income		$ (34,426)			$ (91,239)
Basic (in dollars per share)		$ 0			$ (0.01)
Diluted (in dollars per share)		$ 0			$ (0.01)
Stock-based compensation expense					$ 91,239

[1] As adjusted for change in accounting principle (Note 2)

[2] As adjusted for change in accounting principle (Note 2)

[3] As adjusted for change in accounting principle (Note 2)

[4] As adjusted for change in accounting principle (Note 2)