The key to fasting… don’t make it more complicated than it really is. I’ve been doing IF for three years now and have had great results. My advice… don’t worry about apps to track your fast…stop looking at the scale… when your eating window is open, eat a healthy meal (subjective I know). When it’s time to fast…stop eating. Base your results on how you feel and how your clothes fit compared to staring at a scale. Also…not popular I know, but have a cheat day once a week…I don’t mean gorge yourself, but if you feel like eating some pizza with a soda…go for it.
Just remember… fasting is a rollercoaster. Stick with it and you’ll be fine.