Simple Poll - The easiest way to create polls in Slack
ConversionTracking.com - Track your conversions, see where your sales come from, and optimize your marketing campaigns.
Twitter Polls - Polls embedded in tweets
Weberlo - Weberlo offers cookieless tracking and marketing attribution.
Polls for WhatsApp - Create & share quick polls in your WhatsApp groups
Feather Attribution - A free and tiny javascript library to track UTM tags, ref and referrer data client side so you can store these in your own database.