This covers a whole lot of streams and rivers in the US. It gives the hatch charts for every month of the year for each particular stream and river, and also gives a pic and fly size of all the particular flies suggested. Pretty neat for $.99
This link will change in appearance on occasion since it is the authors blog site. Usually somewhere on the right side of the site you will see something referring to "Hatch 2", if not just do a search. Pretty neat for only $.99
Looks like my home state of Iowa is well represented with just about ALL streams and rivers listed, whereas the State of Georgia is not even mentioned. There will be updates (free as I understand it) coming, however.