Tennis Manager - Feedback

https://play.google.com/store/apps/details?id=com.otm

Can you test my app and give me a feedback to answer question why I am loosing most of players within first week.
My Day 7 retention is only around 5-10 % (5-10 % of install users log in on day 7 after install).

Other metrics look good:
Klick to install ratio: 20 %
ARPPU: 200 $
4 star rating
Average session length: 30 minutes
5 sessions per user per day
150 minutes per user per day
Day 30 retention: 4 %