Stock Plans, Share-Based Payments and Warrants (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Option Activity

The following table summarizes the option activity for the years ended December 31, 2018 and 2017:

	Shares			Weighted Average Exercise Price
Outstanding at December 31, 2016		4,592,347			0.60
Options granted		2,311,542			0.44
Options forfeited or expired		(133,112	)		0.77
Outstanding at December 31, 2017		6,770,777		$	0.55
Options granted		1,143,034			0.62
Options forfeited or expired		(379,250	)		0.46
Options exercised		(100,000	)		0.30
Outstanding at December 31, 2018		7,434,561		$	0.56

Summary of Options Exercisable Vested and Expected to Vest

The following table summarizes the options exercisable and vested and expected to vest as of December 31, 2018 and 2017:

	Shares		Weighted Average Exercise Price
Exercisable at December 31, 2017		2,271,527	$	0.65
Vested and expected to vest at December 31, 2017		6,509,821	$	0.55
Exercisable at December 31, 2018		3,221,236	$	0.61
Vested and expected to vest at December 31, 2018		7,190,188	$	0.57

Schedule of Fair Value Assumptions

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the below assumptions for the risk-free interest rates, expected dividend yield, expected lives and expected stock price volatility.

	Option Pricing Assumptions
Grant Year	2018			2017
Stock Price Volatility		92,42	%		104.56	%
Risk-Free Interest Rates		2.71	%		2.19	%
Expected Life (in years)		6.15			6.11
Expected Dividend Yield		0	%		0	%

Summary of Restricted Stock Activity

The following table summarizes restricted stock activity for the years ended December 31, 2018 and 2017:

	Shares			Weighted Average Grant Date Fair Value
Nonvested at December 31, 2016		957,336		$	0.35
Granted		817,144			0.50
Vested		(975,093	)		0.35
Nonvested at December 31, 2017		799,387			0.50
Granted		449,043			0.62
Vested		(753,528	)		0.50
Forfeited		(45,859	)		0.50
Nonvested at December 31, 2018		449,043		$	0.62