A modular Slingbow/slingshot I designed. The front arrow guide can be removed/added as needed, to switch between being a regular old slingshot, and a sling bow. The yoke itself is modular and removable as well, allowing you to upgrade or replace it in the future, or use a completely different attachment.
The yokes are designed to be minimalist, but still strong and sturdy. As you can see in the pictures, I have a full draw with a full-length arrow (sans head, for safety reasons), and the thing is rock solid.
The grip is hollowed out a bit to lighten the weight, without risking structural integrity. (Seriously, you can beat the ever loving feck out of this thing, and it will be fine).
To give you an idea of how much I trust it, I keep one in my kit as my main slingshot/slingbow.
Base of grip also features a hole for putting on a lanyard, if you so choose to.
Slingshot Bands can be gotten for $10 or less at most outdoors stores/Walmart/Canadian Tire.