There's a couple options for feeders that are more than just a dish, actually.
If you just need a plain dish to offer them in (this is what we do in the stores most of the time), there's inexpensive disposable dishes that are perfect for all mealworm sizes up to Superworms.
http://lllreptile.com/store/catalog...arge-disposable-worm-feeding-dish-water-dish/
There's also a couple "prettier" versions of the same thing, but they do cost a little more.
Small dish:
http://lllreptile.com/store/catalog...-and-food-dishes/-/exo-terra-small-worm-dish/
bigger dish:
http://lllreptile.com/store/catalog...and-food-dishes/-/exo-terra-medium-worm-dish/
There's also this one, but to be fair it doesn't really keep in anything larger than giant mealworms, and those get out too if you put in too many.
http://lllreptile.com/store/catalog...r-bowls-and-food-dishes/-/lees-mealworm-dish/
We've tried these mealworm feeders in the stores, and the beardies in particular figured them out real quick. The only issue I saw with them was that the mealworms kept getting out - so if you put in too many, they'd end up in the substrate. We typically use them in the morning before we intend to clean the cages anyway, so they only have loose mealworms in the cage for a couple hours at most.
http://lllreptile.com/store/catalog...ls-and-food-dishes/-/zoo-med-mealworm-feeder/
They even make ledges if you want to elevate your beardie's worm dish! I use these for my crested geckos and frilleds, not beardies, to be honest, but I don't see why it wouldn't work for beardies in a tall cage too.
http://lllreptile.com/store/catalog...s/-/pet-tech-small-worm-feeder-ledge-granite/
Lastly, for crickets (or for roaches/worms, I suppose) you can always use one of these. I had one in use at the store for enrichment for our baby beardies, and one at home for feeding my baby skinks. They figure out the rock quickly and I like to think it keeps them from getting bored.
Video of the beardies enjoying the feeding rock:
http://youtu.be/hwJFTmbjPaY
http://lllreptile.com/store/catalog...-misc-decor/-/exo-terra-cricket-feeding-rock/
Hope that was helpful!!
I also hope you guys don't mind that I linked to our website - that's where I know for sure to get all these things, and I figured if anyone was actually interested in them in more detail, it'd be easier for them to find them.
You can always search for the same items cheaper elsewhere, but I'm pretty sure we're the cheapest on all of that. In any case, it makes it easier to get the exact name of the product to search for it!
Let me know if you have more questions or if I can help out any more!
-Jen