I like this, I’ve been tracking with MyFitnessPal. Would be great if I could import historical calories to see how it performs. Also note that tracking calories is hard - often it’s an estimate so quite hard to vary by the small amounts above and below the threshold needed for continued weight loss. Also losing weight is hard!

On Android, it supports Google Health Connect.

Users can import up to 30 days of calorie and weight data from other apps that write to Google Health Connect.

Also, yes, Macrocodex doesn’t change your targets for every minor fluctuation in maintenance calories. It only adjusts your target when enough meaningful and measurable change has accumulated, as you correctly pointed out tracking changes below ~150 kcal is difficult.