Note 8 - Stockholders' Equity - Stock Options Activity (Details) - USD ($)	6 Months Ended	18 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Jun. 30, 2019
Outstanding, options (in shares)	7,411,600
Outstanding, weighted-average exercise price (in dollars per share)	$ 1.08
Outstanding, weighted-average remaining contractual life (Year)	2 years 292 days	3 years 36 days
Outstanding, aggregate intrinsic value			$ 20,375
Granted, options (in shares)	390,000
Granted, weighted-average exercise price (in dollars per share)	$ 0.60
Exercised, options (in shares)
Exercised, weighted-average exercise price (in dollars per share)
Forfeited, options (in shares)
Forfeited, weighted-average exercise price (in dollars per share)
Expired, options (in shares)
Expired, weighted-average exercise price (in dollars per share)
Outstanding, options (in shares)	7,801,600	7,801,600
Outstanding, weighted-average exercise price (in dollars per share)	$ 1.06	$ 1.06
Exercisable, options (in shares)	7,801,600	7,801,600
Exercisable, weighted-average exercise price (in dollars per share)	$ 1.06	$ 1.06
Exercisable, weighted-average remaining contractual life (Year)	2 years 292 days
Exercisable, aggregate intrinsic value