Note 11 - Stock Options and Incentive Plans - Restricted Stock Options Activity (Details) - $ / shares	12 Months Ended		37 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Outstanding, shares (in shares)			8,200,000
Outstanding, weighted average fair value (in dollars per share)			$ 0.43
Forfeited, shares (in shares)	(1,525,000)	(875,000)	(100,000)
Forfeited, weighted average fair value (in dollars per share)	$ 0.4	$ 0.4	$ 0.4
Outstanding, shares (in shares)	5,700,000
Outstanding, weighted average fair value (in dollars per share)	$ 0.45
Vested shares (in shares)	2,350,000
Vested shares, weighted average fair value (in dollars per share)	$ 0.56
Non-vested shares (in shares)	3,350,000
Non-vested shares, weighted average fair value (in dollars per share)	$ 0.41