Optimizely is a lower cost entry tool for anyone looking to do website testing. While their pricing structure has changed over the years it still is a pretty cost effective solution. It is easy to get tests up and running within 5 minutes once you have code placed on your site.
I love the drag and drop features of Optimizely. It makes it very easy to make simple changes to do landing page testing for my paid search campaigns. It also frees up dev time for our web team. Also, The findings from Optimizely tests are so valuable for an end customer experience.
Based on our record, Apprecia seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
I had built apprecia: https://apprecia.te.it; but never marketed it. It's a simple tool that lets you send/receive appreciations and store them permanently. It gained 150+ users automatically; and I still use it once in a while to appreciate people. - Source: Hacker News / almost 2 years ago
Evabot for Slack - Send coffee/beer as an appreciation gift to colleagues
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Worthyt Appreciations - Support good content all around the internet
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.
CoffeeRun - Let everyone enter their order for coffee runs
AB Tasty - AB Tasty is an all-inclusive platform for conversion rate optimization, personalization, customer activation, and testing.