It delves far deeper than the two above it. Are you under weight? Or at a healthy weight and under eating significantly? Do you have any other kind of non-diet related HPA-Axis disruption? Lots and lots of studies out there on cholesterol and anorexia. Buuut there are also lots of studies re: huh "bad" cholesterol just from a partial fast diet (i.e. Eating 1500 calories) out there on NCBI. Any kind of suppression of the hormone producing parts of our brain would also cause a spike in bad cholesterol due to the bodies inability to convert cholesterol into hormones. For example, I had high cholesterol as a runner with a BMI of 17. I only now have normal cholesterol at a BMI of 21-22 on about 2K calories and just walking and low intensity exercise.
I'm sure someone will answer your basic question, but cholesterol doesn't work like that. There is cholesterol that some believe causes problems and cholesterol that most believe helps. So your problem isn't cholesterol per se, it's the type of fat you're consuming and also the amount of antioxidants you're consuming usually in the form of fruits and vegetables that prevent cholesterol from sticking where you don't want it to. Basically, you want to limit LDL cholesterol, eliminate triglycerides as much as possible (most often found in hydrogenated vegetable oils) and increase the amount of HDL you're taking in (for example, flax seed oil and fish oil). I don't know about apps, but what you really want to do is learn about nutrition and the food you're consuming.