Downloading and unzipping updates with big amount of files freezes application.

[jplucinski]

Our project is based on https://github.com/Adobe-Marketing-Cloud-Apps/aem-phonegap-starter-kit. Content sync is running on application startup, when splash page is displayed. Users with older devices need to wait up to 30 seconds for app to initialize, that’s why we decided to run content sync in background thread.

Actual result:
Application freezes during content sync on iOS devices.

Expected:
Content sync runs in background thread on all devices.

[macdonst]

@jplucinski I know you did some work on this. Do you want to send a PR?