I’ve got a Tribit Maxboom and it’s great. Water resistant, line in plus Bluetooth, has a handsfree button (triggers Siri on iPhones) and volume up/down, plus a bass boost mode that uses more power.

It doesn’t drive as much sound as my portable guitar amp, but for a battery based speaker, does pretty well. If you buy two of them, they’ll figure out how to work together to provide surround sound, otherwise a single one will play stereo audio to fill the area.

Had it for around 6 years and it still holds a charge like the day I bought it (I usually need to charge it every couple of months).