Coreo is a very user friendly piece of software to use. I've tried using other systems before and never managed to get them to work properly (or at all). Coreo is really easy to set up and they've obviously spent a lot of time thinking about how people do surveys and have designed the app accordingly. They also have some great templates for protected species surveys as well as a really good UKHab/BNG system - I basically couldn't function without that now.

That you can have everything in one place.