American Airlines and AwardWallet announced yesterday that you can again monitor your AAdvantage account balances using the AwardWallet service.
There are several services that you can use to monitor your miles/points balances from number of programs and AwardWallet is one of them.
There are airlines such as American that you could originally monitor, but that were later removed at their request. It is more profitable for the airlines just have the miles expire unused than have members actually to burn them.
I am not personally using any of these tracking services, but can see the benefits of using them for some.