Auto Capitalise Sentence has never collected and will never collect any personal data, browsing history etc.
In future Auto Capitalise Sentence may collect browser version, platform name, display settings and user's filter settings (except website list or any other data which can help identify user). This information is needed for decision on implementing new features, removing unused features or suggesting default settings for new users. It will happen only with your permission.
Auto Capitalise Sentence uses browser's Web Storage API (localStorage) for storing user's preferences.