We've used quite a few Bluetooth speakers this year, but none of them have been as small as the Bluetune Bean from Divoom, although there was the Jam XT from HDMX which I really did like. Plus the color was much better in my opinion. This one is pretty small, in fact it's smaller than the Nexus 5, although it is quite a bit thicker, but that's expected since it is a wireless speaker after all. . The Bluetune does have a built-in microphone, it's also pocket sized and has big wireless sound. Not to mention the clip-on design. The Bluetune is a great looking speaker that comes in a variety of colors. Including blue, yellow, red, pink (the color I've got), white and black. It's also pretty cheap at only $29.99.
I've been using the Bluetune Bean speaker for quite a while now (about a month to 6 weeks). And it's done quite well in my opinion. It's been able to last all day listening to Google Play Music and such, without needing to be recharged. It does have a clip on design, so I was able to clip it to my keychain and use it, although that's not all that impressive, since it's much heavier than a bunch of keys but it does work. It seems to be made out of the same type of material as the Nexus 5 and the Nexus 7, which is good in my opinion. I'm a fan of that type of material, especially on a speaker. It comes with an attachable clip, USB charger and a built in Bluetooth adapter. I'd have to say my only gripe about this speaker is the Bluetooth connectivity. It doesn't seem to remember the devices you've connected to, so you have to put it in discovery mode every time. Now I thought this was my devices fault (since I am on KitKat) but it didn't happen with other Bluetooth devices.
Divoom also has plenty of other Bluetooth speakers available and all seem to be pretty affordable. For a speaker this size and at this price, I was actually pretty surprised at how good the sound quality was in it. You can grab the Divoom Bluetune Bean from Divoom's website or Amazon for $30.