> For the complete documentation index, see [llms.txt](https://docs.atsign.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.atsign.com/atsdk/sdk/synchronization.md).

# Additional Features

Some atSDKs have additional features, usually due to some technical reason. You can find a list of those features and which platforms/implementations support them here.

<table><thead><tr><th width="214">Feature</th><th width="318">What it does</th><th>Platform(s) Supported</th></tr></thead><tbody><tr><td><a data-mention href="/pages/z8byaPIewXlZsGioRFLU">/pages/z8byaPIewXlZsGioRFLU</a></td><td>Offline support for apps</td><td>Flutter / Dart</td></tr><tr><td><a data-mention href="/pages/nNe8YAzRoeNCVIthlNVD">/pages/nNe8YAzRoeNCVIthlNVD</a></td><td>Control the connection lifecycle</td><td>C</td></tr></tbody></table>