There is a free web page behind the Delta ALPA wall located at MYALPA>>MyMEC>>Dashboard>>Pilot Dashboard

There is also a private site WidgetSeniority.com which I think lets new users have the service the first year of their employment as an incentive.

You can gather the same information from iCrew at Bids>>Relative PositionWithin Category for Next Bid Period.

iCrew is the most accurate, followed by Widget Seniority and ALPA. All tools are very close. Someone might have better information, but the small differences are likely folks who are on leave or not bidding for some reason or another.