Envoy - Visitor registration that's changing how guests are greeted in companies around the world.

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.

TractionGuest - Safe, secure workplace for all.

Google Custom Search - Google Custom Search enables you to create a search engine for your website, your blog, or a collection of websites.

The Receptionist - The Receptionost is a visitor managemnt solution that has visitor logging system to track visitor traffic.

ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.