It's free and open to the public. The team usually signs autographs afterward, too. Last year fans could work their way down to the front rows and players would float around and sign what they could. One other time I went, they had tables set up in the North concourse, and you could just go through the line. So I don't know what they'll do for that this year.
I found a small burb about the spring game on www.hawkeyesports.com. Go to the football team page the click on calendar to see it. Looks like it starts at noon on April 16th. I think it has always been free in the past.
The game is at noon and is free. Thanks for the information gang.
Also hear the The Iowa Hawk Shop is going to set up the annual Spring sale in the concourse by Gate M. The sale goes until 1pm, but I am not sure what time it starts.