From Deaf&Drum:

Finally, a place to put a drink or two, some spare sticks or mallets, your phone, car keys, wallet, IEM/Earplugs or whatever while you're playing.  No more kicking your keys off the drum riser or knocking over your water bottle while you're playing.
The Drum Buddy is the solution.  8" diameter x 3" deep and lightweight 3d printed out of ABS or PETG.  

Drum Buddy Bigmouth:

1 - 3.5” Drink Holder

1 - slot for phone w/ charging slot

6 - holes for sticks

1 - hole for drum key

1 - large space for keys, wallet etc

1 - hole for Sharpie

It will mount to a standard tom mount (L-clamp or cowbell mount) with the supplied tom mount bracket.

Note: This is the new model of the Bigmouth and is made with holes on both sides to add the flexibility of moving the tom mount clamp if you wish to mount this on the opposite side of your kit. It will also have a center hole to allow usage of a crab clamp instead of the chrome tom mount. Anything listed with the text "Dual Mount" will have this capability.