Note 12 - Stock Options and Incentive Plans - Restricted Stock Options Activity (Details) - $ / shares	9 Months Ended	12 Months Ended	49 Months Ended
	Jan. 31, 2025	Apr. 30, 2024	Apr. 30, 2023
Outstanding, shares (in shares)			8,286,704
Outstanding, weighted average fair value (in dollars per share)			$ 0.45
Forfeited, shares (in shares)	0	(1,525,000)	(975,000)
Forfeited, weighted average fair value (in dollars per share)	$ 0	$ 0.4	$ 0.4
Outstanding, shares (in shares)	5,786,704
Outstanding, weighted average fair value (in dollars per share)	$ 0.47
Vested shares (in shares)	2,528,901
Vested shares, weighted average fair value (in dollars per share)	$ 0.52
Non-vested shares (in shares)	3,257,803
Non-vested shares, weighted average fair value (in dollars per share)	$ 0.43