UPDATE 4-18-16. Perfect. My #1 app. Syncs everywhere and never ever fails to deliver. The app I use the most on iphone.
UPDATE 9-27-2015.
Yep. Still the Best. Another app update, and more improvement. My iphone is my constant assistant, and CalenGoo is the most-used app I have. Always reliable. Always amazingly helpful. Just superb.
UPDATE 5-12-2015: If you look at all choices in "Settings"--> "Display and Use" --> "All", you will find tons of goodies that make the CalenGoo experience one of a kind. This is my go-to app for my entire schedule, which is packed with professional and personal items. CalenGoo handles it all effortlessly. Also... I add events with Siri, through the Reminders native app. Incredibly efficient. UPDATE 3-27-2015: This is my most-used app. I rely on it multiple times a day, on both iPad Air and iPhone 6.
UPDATE 4/7/14: CalenGoo is a gem. Flawless. Ive used it many times a day, for a few years now, on both iPhone and iPad. See previous reviews below:
Original: Finally Retired my Paper Planner! CalenGoo has been my go-to app for a long time. Easy to use, highly efficient, speedy, reliable, and adaptable. I have color-coded everything, which adds to the usefulness (one little example is I have set it up so that the current day always appears a bright yellow, no matter which calendar view Im using--day, week, or month).
I no longer use: my paper planner, my notebook to-do list, Googles on-line calendar, my iPhone calendar, or any other reminder system. CalenGoo does it all, and much faster.
I send reminders to myself via text message and email....and can set those up for next hour or next year. I can add Tasks very quickly, and editing anything is so very simple.
Keeping order to my hectic schedule is efficient, and always very easy to revise.
Automatic syncing assures me that all info is on my iPhone and iPad.
CalenGoo works off-line. It is feature-rich and highly adjustable. It is absolutely essential.
Update: I love "Floating Events"! When I have something I need to do soon, instead of sending myself multiple reminders, I now set it up as a "Floating Event", "All Day". So the task will appear on my calendar today, but does not clutter up any other day. If I dont mark it as done, then it moves itself to tomorrow automatically. It can have an end date, so wont float indefinitely.
CalenGoo continues to help me be more productive, because its quick to enter and edit tasks, events, and reminders, it syncs flawlessly with Google and ios calendars, as well as perfect sync between iphone and iPad.
Update: Used many times every day for two years! Never had problems syncing or with anything.
Update: The more Ive used CalenGoo, the better it gets...because Ive tweaked the settings and colors to be perfectly suited for my needs.
Update: Even better with the updates! I continue to rely on Calengoo to keep me organized.