Tally

When I first downloaded Tally, I was mostly expecting a way to see all my credit cards in one place so that I could pay them off all at once. This is convenient since if I have multiple credit cards, it's pretty annoying to log into each individual credit card account and pay them off one by one. Tally does this for me, while it doesn't support all credit cards yet, they still support a good amount of cards and are still expanding.

What surprised me, though, is that the way they do this is by giving a new credit line. This credit line is only used as a placeholder for paying off other credit cards, and in some cases gives you a lower APR than your actual credit cards if you want to migrate credit debt over (can see site for details). Then Tally figures out the best way to pay off your credit cards while maximizing rewards and minimizing interest. Sweet!