We recently started a pilot of Zumero.
To sum up what Zumero is about (from their site):
“In the world of mobile apps, the network is the least reliable part of the story. Zumero’s “replicate and sync” database approach is faster, more reliable, and works perfectly offline. Zumero keeps a copy of the data on the device, so database operations do not involve the network. Zumero handles synchronization with the server in the background when a network connection is available. Users never have to wait or worry about being offline.”
We have built custom mobile apps a number of ways involving data and it can be quite a task to manage the transfer of data between devices and a central database. Zumero started out as an open source project. We tried it through our Xamarin development and were very impressed and now that it’s a commercial venture it appears to have quite a few new features that make it a real contender for this growing area of mobile app development.
They have both a self-hosted and cloud-hosted offering and prices vary by the number of users/devices.
We’ll report our findings as our pilot project evolves.