I don't, actually, but I agree, based on what has worked best for my DD, skip counting is a huge help here so stay with that and definitely work on one fact for an extended period before shifting to another fact. Also, have her create a math chart every week or two for multiplication facts so she can start to see the relationship between the numbers.
But also, don't get too hung up on math fact fluency. While it is really helpful to have (really helpful), and I would continue to work on it, this is not the be all and end all of existence. Truly. Lots of people never successfully memorize all of their math facts and are still successful as adults.
DH does not have all of his math facts memorized. He is still a very successful engineer.
I do not have all of my math facts memorized. I run the business finances for the family business and was commended by my mother's CPA for how I have taken care of everything since my dad passed away.
My brother in law does not have his math facts memorized. He is also a successful engineer.
My mom was never able to memorize all of her math facts but she did very well as a High School Reading Specialist.
A nurse friend of mine has learning challenges, never was able to memorize her math facts, but is excellent at skip counting. Super fast. She was able to use that to pass standardized tests and is a very successful nurse. She also teaches nursing classes at the college. She says that the best possible skill someone can have as a nurse is understanding the numbers and their relationship to each other, NOT rote memorization of math facts. Calculators can do math facts but a calculator cannot think logically about the numbers. That is where the human brain can excel. Logical thinking and understanding number concepts/relationships is far more important, in her honest opinion.
In fact, she demonstrated something to me that really helped me see what she was talking about. She knows that DD has dyslexia also has dyscalculia. Math is HARD for DD. And memorizing math facts is really, really challenging for her. The nurse friend gave her a puzzle she gives all of her incoming newbie nursing students. They have to take medication that is in one type of measurement and convert it to another type of measurement to be able to administer the correct dosage since the doctor's orders are written for one kind of measurement and the medication is distributed a different way to hospitals. DD looked at the word problem and was like a dear in headlights. Nurse looked at her, told her to draw out the items involved and just THINK about what was being asked. DD drew out the two different items of medication. Light bulb went off. She knew the answer. The nurse said 90% of incoming students insist they cannot do the problem without a conversion chart to convert between the two measurement systems. DD realized that you don't need a conversion chart or any real math at all. The way the information was provided, if you just sat and thought about it a bit, the solution is based on logic, not math.
What she was trying to say was this: When a nurse is going to administer your medication, do you want the person who rote memorized their math facts but never really understood the connection between the numbers and/or was never able to think logically about those numbers or would you rather have the other person who might struggle with memorizing math facts but can THINK? The person that can THINK may look at your dosage and realize the decimal was transposed because the dosage is not logical for a person of your size/body weight. The person that can THINK about those numbers might realize enough to know something is wrong and ask questions instead of just doing what they were told. Someone who was never really good at THINKING about numbers but can rattle off their times tables in nothing flat might not question it at all.
Anyway, sorry that got so long winded.
I do wish I knew an app that would track math facts AND work only on one math fact at a time. Hopefully someone else can provide a suggestion. Good luck.