I love how easy it is to use. It's very simple to create campaigns and send them out. The interface is also nice and clean which makes creating new content quick and efficient! There are some other apps that have more features but this one has been working just fine so far. Honestly, nothing at all really. If you're looking for an app like Castanet then we do not recommend purchasing from another platform as they don't offer enough in terms of benefits compared to their price point. We were able to quickly get our sales force up to speed using Castanet by making sure everyone was following through with our training program. This made us feel better about having such a large team without being spread too thin across multiple platforms.