The vision of an augmented reality (AR) cloud is about an enhanced version of the real world extended by persistent, location-anchored digital objects. We present a fully open source, end-to-end solution for placing, storing, and re-discovering geo-anchored AR contents in the real world. We advanced various components of the Open Spatial Computing Platform (OSCP) and deployed it in a 5G testbed. We created a new OSCP reference client in Unity and built representative demo applications that allow virtual objects to persist throughout space and time. We created a data collector application for spatial mapping, and we connected the OSCP with an open-source visual positioning system. Furthermore, we created tutorials on the setup to foster its adoption in the scientific community as a platform for location-based AR experiments.