Upload your Binding of Isaac: Rebirth savegame file and I'll tell you some stats, as well as list missing items and achievements. To see an example, have a look at one of the recently uploaded savegames below.
Tested with savegame format produced by BOIR versions 1.04x and 1.05. Your
savegame should start with the string
Locate your savegame
Savegame files are named
Savegame locations when installed via Steam:
c:\Program Files (x86)\Steam\userdata\********\250900\remote\
Upload your save
Stats are found manually, by playing the game and looking what's changed in the savegame file after each save.
All uploaded files are made public. However, no personal data is collected, displayed or forwarded.