It appears most applications are writing custom logic to sync/replicate cloud data, or utilizing a platform locked service like iCloud.

What mix platform data sync solutions are available besides roll your personal? By "solution" I am talking about well examined mixtures of server and client components.

The 2 I understand of are:

  • CouchBase Mobile (CouchDB on server, CouchDB on device)
  • Microsoft Sync Framework (SQL Server on server, SQLite on device)

I understand they are quite different data stores, but data solution that's generalized for a lot of problem types may potentially reduce some wheel reinventing. For instance I might need NoSQL for just one application and relational for an additional.

Every other options besides both of these?

Sybase SQL Anywhere Studio has UltraLite database as part.
This database has versions running on iOS, Android, Rim, and allows you synchronize through HTTP/HTTPS