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.
iManage Work - iManage Work Product Management helps to organize and track the complete lifecycle of a professional engagement.
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
Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
APKMirror - Android Market and APK Downloads
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.