I’ve been approached by the developer of a nature app to use my photos of two species of birds for their app. They’ve asked my expectations for licensing. I sell prints occasionally but have never licensed a photo for a use like this and I have no idea what to charge. I don’t care that much about the money - licensing two photos is not exactly going to impact my lifestyle after all. I just think it would be neat to have my photos used in the app. But they are using it for a commercial purpose so they should pay something. I definitely don’t want to be greedy and I’m not a professional, but I also don’t want to harm actual professional photographers by undercutting the market. Any suggestions on what an appropriate range is for a licensing fee in this context would be much appreciated. Thanks.