I don't know who out there besides me keeps an African Dwarf tank but I've maintained a 10 gallon with three frogs for a few years. I've primarily been hand feeding them defrosted frozen bloodworms and occasionally a high quality pellet. They are used to getting fed in the front right area of the tank and I recently decided to streamline the process and make a frog straw.
I made a new tank lid from multiwall polycarbonate, drilled a hole in it, and have run an acrylic tube down to where they're used to being fed. The inside diameter of the tube is 8mm so I don't think there's any danger of escape—at best they could stick their snout in it.
Instead of defrosting and hand feeding, now I can drop frozen worms in the tube. As they defrost, they drop to the feeding area. The frogs will notice the smell in the water before they drop and start to gather (three raps on the tank also signifies feeding time for them).
I wanted to share this in case anyone is looking for an easier way to feed their ADFs.