I used to use (Wow, what a word play ) the GD investor app to track auctions but I left my $5 auction membership expire, I don't think I'll renew it and without it, it's worthless to monitor GD auctions.
Otherwise if you bid on GD expiry auctions from time to time, it's not too bad of an app, it does its job more or less, with a few bugs here and there but you'll get used to it