Share-Based Payments

The Company has in place a 2010 Equity Incentive Plan and a 2008 Equity Incentive Plan. In general, these plans provide for stock-based compensation in the form of (i) Non-statutory Stock Options; (ii) Restricted Stock Awards; and (iii) Stock Appreciation Rights to the Company’s employees, directors and non-employees. The plans also provide for limits on the aggregate number of shares that may be granted, the term of grants and the strike price of option awards.

Stock-based compensation in the amount of $148,000 and $535,000 was recognized for the three months ended October 31, 2017 and 2016, respectively, and $711,000 and $1.7 million was recognized for the six months ended October 31, 2017 and 2016, respectively. Included in stock-based compensation expense for the the six months ended October 31, 2017 under general and administrative line item is an option modification charge of $56,529. Stock-based compensation expense was recognized as follows (table in thousands):



	Three Months Ended October 31,				Six Months Ended October 31,
	2017		2016		2017		2016
General and administrative	$	96	$	469	$	519	$	1,298
Sales and marketing	7		18		41		187
Research and development	42		45		122		130
TOS cost of sales	3		3		28		47
POS cost of sales	—		—		1		2
Total stock-based compensation expense	$	148	$	535	$	711	$	1,664

On October 31, 2017, there was $160,365 in unrecognized stock based compensation which will be recognized as expense over 2.5 years.

Stock Option Grants

Black-Scholes assumptions used to calculate the fair value of options granted during the three and six months ended October 31, 2017 and 2016 were as follows:



	Three Months Ended October 31,		Six Months Ended October 31,
	2017	2016	2017	2016
Expected term in years	6	6	6	2.6 - 6
Risk-free interest rates	1.98%	1.48%	1.98%	0.75% - 1.48%
Volatility	87.1%	87.32%	87.1%	73.2% - 95.6%
Dividend yield	—%	—%	—%	—%

The weighted average fair value of stock options granted during the three months ended October 31, 2017 and 2016 was $0.00 and $1.16, respectively, and $1.84 and $1.73 was recognized for the six months ended October 31, 2017 and 2016, respectively. The Company’s stock options activity for the six months ended October 31, 2017 was as follows:



	Non- Employees	Directors and Employees		Total		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2017	50,000	2,258,704		2,308,704		$	2.86	6.1	$	1,282,000
Granted	—	194,977		194,977		2.51		9.7
Exercised	—	—		—		—
Forfeited	—	(6,042	)	(6,042	)	7.58
Canceled	—	—		—		—
Expired	—	(2,709	)	(2,709	)	8.44

Outstanding, October 31, 2017	50,000	2,444,930		2,494,930		2.82		5.9	$	2,512,000

Vested and expected to vest as of October 31, 2017	50,000	2,444,930		2,494,930		2.82		5.9	$	2,512,000

Exercisable as of October 31, 2017	33,336	2,391,889		2,425,225		2.81		5.9	$	2,484,000

Stock Purchase Warrants

As of October 31, 2017 and April 30, 2017, the Company had warrants outstanding for the purchase of 2,004,284 shares of its common stock, all of which were exercisable. Activity related to these warrants, which expire at various dates through March 2020, is summarized as follows:



	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2017	2,004,284	$	5.57	2.8	$	—
Granted	—	—		—	—
Exercised	—	—		—	—
Expired	—	—		—	—

Outstanding, October 31, 2017	2,004,284	$	5.57	2.3	$	—