API to bot - Convert your API to Alexa skill or Google Home app in 5 mins
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.
Jovo - 🗣 Build cross-platform apps for Alexa and Google Home
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
Voice Principles - Guiding principles for voice design, all in one place
APKMirror - Android Market and APK Downloads