If you really want to get one, you can consider
Eheim Everyday Fish Feeder(see the links below).
But do take note of the common problems with the auto feeder.
The main problem/difficulty is in ensuring that it dispense the right amount of food.
Some auto feeder has a very big opening for the dispenser and it can accidentally dispense too much food.
And sometimes there is no food coming out from the dispenser if you open too little or if you don't adjust the opening properly.
You have to test the auto feeder outside the tank first before you hook it to your tank just in case too much food is dispense from the auto feeder.
Firstly, put a piece of old newspaper on the floor or table to collect the food that will be coming out from the auto feeder before you perform the test.
Then, by holding the auto feeder with your hands over the piece of newspaper, press the start button for the auto feeder to dispense the food.
Keep adjusting the dispenser's opening until it dispense the right amount of food.
You have to try it a few times until you are confidence that it dispense the right amount of food.
I hope you can understand my explanations.
Anyway, take a look at the websites below:
Automatic fish feeder is mechanical device that periodically add fish food to the aquarium. The devices have been popular in the hobby for over 30 years.
perfectfishtank.com
With an automatic feeder you will be sure that your fish are always properly fed, no matter what. Check out our list of the best automatic fish feeders!
www.gearhungry.com