The Vamp - Transform any speaker into a portable Bluetooth® speaker
F-Droid - F-Droid is an interesting alternative for Android users who want to try something different and not have to use the Goole Play store all the time.
Sonos Out Door Speaker - An outdoor speaker developed by Sonos and Sonance
APK Pure - Download apk for Android with APKPure APK downloader. NoAds, Faster apk downloads and apk file update speed. Best of all, it's free
BOSEbuild Speaker Cube - Build-it-yourself Bluetooth speaker for curious kids
APKMirror - Android Market and APK Downloads