QR Droid - QR Droid Zapper
Officely - The only desk booking tool that lives in Slack
QuickMark - QuickMark makes everything possible.
OfficeMixer - Automated office bookings
Barcode & QR Code Scanner - A free app which allow to read and generate barcodes for Android.
RobinPowered - Robin coordinates meeting spaces, people, and things in your office. Complete with analytics and insights that uncover usage and help optimize space.