I have a Satechi Bluetooh remote that is a little circle. It plays/ pauses & does the volume and that's about it. I take it when I travel to use as a remote for the iPad hooked up to a TV. It works great. I just looked it up on Amazon & here's the name they use (Sorry about the large font below, I copied it from Amazon & I don't know how to reduce the size in macrumors):
Satechi Bluetooth Button Series (Media Button) for iPhone X/8 Plus/8/7 Plus/7/6 Plus/6/, iPad Pro/Air 2/Air/Mini/3/2/1, Samsung Galaxy S8/S7/S6, Note 4/Edge/Pro/Tab Pro, Google Nexus 9 and more