I need help.

My daughter found a tiny tadpole in her friend's swimming pool and brought it home. I placed it in a 2.5 gal tank and against all odds it made it. It has also totally morphed into a frog within less then a month. It still has 3 mm of tail left but at the rate is it disappearing it should be gone by Sunday. I am still not sure what frog it is but I am positive we can rule out bull frog due to it's small size. He is only 3/4 of an inch at this time. I am at a loss as to what to feed him now. So far as a tadpole I fed him fish food, tadpole and turtle food as well as frozen bloodworms and algae wafers. Now that he has morphed, he will not go back into the water unless pushed and I am afraid he might starve. What can I feed him? Or should I release him back into the area where my friends pool is? I have daphnia, microworms, vinegar eels and grindal worms as live foods and since I live in Atlanta I could easily cultivate mosquito larve, but if he does no longer go into the water none of those will work. Any advice would be welcome. Also if I posted a picture of him on this site could anyone identify the frog? Right now he is 3/4" almost morphed and totally brownish/green no special markings.
Any advise would be welcome. We really like the little guy and even so we know it would be best to release him the thought of a bird getting him makes this hard to do. I have several larger tanks I could convert to a frog tank like a 10 gal hex but unless I can figure out what and how to feed him I am more afraid of starving him than what the birds could do to him.