Review on Kronomos by Andrew Enriquez

The most useful feature for me was that I could see how many people were open with my emails at any given time - so if it wasn't getting read or opened then you knew right away! It's also great when trying out different layouts/ designs as well which can be really helpful in terms of finding what works best within your target audience; however this may take some trial & error before seeing results (as there are several factors affecting conversions). Although not very obvious from looking through their website they do offer 1-on1 support via phone call / Skype but unfortunately we never got around doing one ourselves due more urgent issues than technical ones occurring during our testing phase..