They include MileageManager, Acruw, Mileport, AwardWallet and MileTracker.
I had planned to do a comparison of the various programmes, though that wouldn't have been much of a challenge to any website since I really only use one airpoints programme and my wife has just two (she did have a third but I suspect the points there are long expired). For all practical purposes these days we only have Air New Zealand airpoints dollars which are extremely easy to manage.
Fortunately I found an article by Los Angeles Times journalist Scott J Wilson, who is in the happy position of having 23 frequent-flier programmes in his household, the managing of which would be a good test of any programme.
He concluded that AwardWallet is the best option because it lets you enter multiple accounts, shows all the points and expiry dates on a single page and, best of all, sends a warning email when miles are about to expire.
If, like my wife and I, you've only got a couple of accounts, you can do all that for free. But if like Wilson you want to list more than three you need to take out a paid membership. Fortunately that's not too expensive because the level of payment is voluntary.
In fact Wilson got away with offering only US$1 a month... though AwardWallet "did try to shame me by noting that some people pay as much as US$40 for six months".
If you've got a lot of loyalty programmes you have difficulty keeping track of then that sounds like a pretty good investment.