New Delhi, Feb. 5 -- Indians find it easier to ask strangers for directions inside a hospital, airport or office park than open an app. That workaround, however, is beginning to fray as campuses, hospitals, airports and logistics hubs expand in size and complexity.

Indoor navigation is increasingly being pitched as the next layer of digital maps. Yet, scaling it has proved far more complex than building outdoor navigation.

The reasons are structural. GPS does not work reliably indoors, indoor maps are privately owned rather than public goods, and each building requires custom mapping and permissions, making scale far harder to achieve.

Even companies that cracked indoor location intelligence stopped short of full navigation. Peter Thei...