Note 6 - Share-based Compensation - Stock Options (Details) - 2018 Equity Incentive Plan [Member] - USD ($)		6 Months Ended
		Dec. 31, 2018	Dec. 31, 2018
Options outstanding, granted (in shares)		1,318,517
Weighted average price per share, granted (in dollars per share)		$ 0.34
Options outstanding, balance (in shares)			1,318,517
Weighted average price per share, balance (in dollars per share)			$ 0.34
Aggregate intrinsic value, balance	[1]		$ 1,000
Minimum [Member]
Exercise price per share, granted (in dollars per share)		0.22
Exercise price per share, balance (in dollars per share)		0.22	$ 0.22
Exercise price per share, balance (in dollars per share)		0.22
Maximum [Member]
Exercise price per share, granted (in dollars per share)		0.43
Exercise price per share, balance (in dollars per share)		0.43	$ 0.43
Exercise price per share, balance (in dollars per share)		$ 0.43

[1] Aggregate intrinsic value based on closing stock price of $0.24 at December 31, 2018.