If it were me installing your app, I would uninstall it for lack of enough features. (I did not actually try your app, maybe I will.)
Some things that appear to be missing (from the google page, I didn't actually try it):
A way to sleep/snooze a reminder for a specific period of time.
Per-todo item auto-sleep rules. (Sleep, and just stay as a notification? Sleep and go away? Sleep and alarm again?)
Options for what kind of alert - noisy, quiet, speak the alert, buzz, start quiet, get louder. (All per todo, not global.)
Does it turn on the screen when there is an alarm? It shouldn't.
A guarantee that no alerts will be "lost" if the device is off when the reminder should have gone off.
Way, way more flexible options for reminders. You need things like: Remind for 4 days, then sleep for 2 weeks. Or every other week, but only on these days of the week. There are many patterns.
They way you program that is start with a basic repeat, then you add exclusions, "not on these, days/weeks/months/dayofweek".
Next you add "don't start until date", and "stop after date".
Then you add unlimited "don't alarm on this date", and "alarm on this date", where they just add a list of them.
Next you need multiple alarms per todo - the first one is just a notification, and if I dismiss it the rest of the alarms go away. The next alarm is a short quiet one. And then a loud one. But the user picks what kind of alarm, and how much before the event. They can add as many pre-alarms as they like.
I have not found a good reminder program, very very very few have flexible enough reminders. The best I've found is https://play.google.com/store/apps/details?id=com.splunchy.a... - install it just to check out how to do complex alarms, and complex repetitions. It's a beta though, with bugs, so I'm not suggesting it for use, just to see examples.
Do you want to make a comprehensive alarm program? Or do you want something simple? There is a market for both.