The app Phases of the moon (Android) lets you put a moon widget on your phone so you always know what moon phase it is. If you have an iPhone, you may want to try Moon Phase Calendar Plus.
Lately I have been using SkyView Free (Android) and on iPhone for watching the sky in general. It includes the Moon and every other observable body, last night I identified Saturn and Jupiter!
For lunar spellcasting, of course I will recommend you the Spell for Today page since it generates a quick candle spell for every lunar phase.
If you’re on desktop, I like the website Moongiant which includes other extra features.
Also, I usually send emails through the Spells8 newsletter where I include celebrations for the New Moon and Full Moon. But in my opinion, the best way to track the Moon is to look up everynight and try to find it!