ClickOnce is a great technology to handle change management for applications in the field. Unfortunately its support is a bit confusing. Especially, if you are writing SQL Server Compact Edostion (SSCE) applications. SSCE claims support for ClickOnce, which is correct only for applications based on the normal .NET Framework running on desktop or tablet PCs. .NET Compact Framework apllications are unfortunately left behind. So, be awrea of this. It is, at least in my eyes, really a missing feature.
Of course, You are able to create something similar using the SSCE synchronisation features yourself, but this means to develop infrastructure code that ideally should come with the platform you are developing on.