TapTalk.io - TapTalk.io is a complete in-app chat SDK and messaging API - Easy integration and customizeable.
Procore - Procore is the world's most widely used construction project management software. Easy to use, mobile platform with unlimited user licenses.
Lets Chat - Open source self-hosted chat app for small teams
CoConstruct - CoConstruct's project management software helps custom builders & remodelers coordinate projects, communicate with clients & crew, and control.
WeChat API - WeChat API and SDK allow developers to access and integrate the functionality of WeChat with other applications.
BuilderTREND - Buildertrend is the #1 construction management software and construction app for home builders, remodelers, specialty contractors and commercial construction.