Just released a small update which adds an option to make notifications active/accurate even when the app is closed. To see the option, simply disable and enable notifications again and it will show up.
(Most phones will put the app to sleep if it hasn't been used/opened for a few hours, which makes you miss notifications. To avoid that, you can use the new option to disable sleep/optimization for the app)
Top! Keep going friend!! I will check it out as soon as possible