Informant supports multiple settings for determining when the application syncs its data.

In the Informant settings, sync accounts, there is a setting for AutoSync, tapping this setting will open all of the available options and you will just need to select the sync option that best fits your needs.

Selecting the "new and changes" option will sync Informant when the data is changed inside of the application only.

Setting a short sync interval such as every 5 minutes or every 10 minutes will reduce battery life.

This does not apply to iOS data when being used in Informant.  The sync interval of the iOS data is determined by the device itself not the Informant settings.