The premise of Simple Poll is to keep most of the User Experience within Slack. Simple Poll makes an effort to store the minimum amount of data for the best possible User Experience as well as analytics to improve the Simple Poll experience.
The data that you pass to Simple Poll is stored, so that interaction with the Slack API is possible and so that you can manage your own polls in the best possible way. This includes the poll content, votes, access token, team and user metadata, the time at which Simple Poll was added to the team, and the time at which Simple Poll was last authorized.
Explicitly NOT stored data
By design, Simple Poll has very little access to your team's data: Simple Poll cannot view a lot of information about your team: it cannot view any activities in any of the channels and it also does not have access to any of your files. The only data it can access is the data that you are sending via button presses (to for example vote) and slash commands (/poll "Question?" "Option1" "Option2"). In this example Simple Poll will receive the text of the slash command, namely '"Question?" "Option1" "Option2"'. This data is stored solely for the purpose of you using it at a later stage, to for example manage your own polls.
Simple Poll uses analytics tools such as Google Analytics, New Relic, Opbeat, and Keen to monitor performance and to improve the user experience. Collected statistics are, for example, in the form of frequency of invocation of the /poll slash command over time.
Third Party Services
Simple Poll does not display any advertisements, and does not share any data with advertisers.