Hello,
I created a project for training and analyzing your performance during contests: cp-trainer.com. I believe it has some unique features not existing in competitive platforms and can provide as a more sensible tool for training, especially for more experienced users. Below I will briefly discuss its functionalities:

Problem recommender

Contest training picker

User stats

Compare yourself against the others

The idea for this section was to analyze for the user, how much he is worse than the average contestant with some specific rank. It was realized by taking statistics for 40 average random users across that specific rank , who participated in >=50 contests and were registered min 3 years ago. (that should approximate well the random user with some rank.)

We can see in the picture above the sample statistic of me compared with the average grandmaster telling what is the average time difference (in seconds) of solving problem with some specifing rating. As we can see, I am slower on the most of the ratings, especially in the hardest ones.
The included statistics are (the time unit is in seconds):

• Average time difference by tag — Average time difference with problems of specific tag.
• Average time difference by rating — Average time difference with problems of specific rating.
• Average accuracy difference — Average number of submissions difference to accept the problem with specific tag. It can help to understand on which type of problems we have more problems in implementation.
• Average highest solved problem — Average rating difference of the hardest problem solved in the contest. This helps to understand how much higher rated problems should we solve on average in the contest to be able to get some specific rank.
• Average lowest unsolved problem — Average rating difference of the problem with lowest rating unsolved in the contest.

Note: The green bars mean there is contestant's advantage, red otherwise.

Summary

The goal was to create the tool which will analyze user's performance during real contests and then based on that propose adequate problems for training. Most of the apps focus on the stats of the user also during practice, that in my opinion don't provide the best insight e.g. because outside the contest you have unlimited time and also you can look at editorial.

If you find any bugs, please let me know and I will try to fix them as soon as possible. Any constructive criticism is also appreciated. Thanks for checking out the platform.