How do you import sessions from another app or excel sheet?
Options > Settings > Import Sessions
Go to options by pressing the button at the top right of the profile page. Under "import sessions" there is a spreadsheet template to correctly input your old sessions. Once that's completed you can use the import data button and send it in from iCloud Files, Google Drive, Dropbox, etc.
How do I share sessions with friends?
All you have to do is swipe left on a session and there will be a blue "share" option. You could also tap on the session and hit the share icon.
How do I look at advanced statistics?
You can either hit the arrow on the top right corner of your graph in the profile tab or go to:
Options > Stats
Don't forget you can also filter the advanced graph and stats by various criteria such as stakes, game type, location, etc.