This could end up being moved over to Smorgasbord, that's where I stumbled on the reference to the Walla.by app. So I added it to my phone. Got sucked into adding all my cards to this comparison tool, which has a "Best Card" window where it proposes, of your cards, based on the setup you have for those cards, and available categories, which card should be used for the "best" rewards.
I assume this does not factor in annual fees. Once you have the card in your wallet, the app would presume "Ok, this person has committed to the AF. Now what is best?"
The first set, on the left, includes my current card lineup with AMEX Delta, CapOne Quicksilver, US Bk Cash+ set to Groceries 2%, Department Stores and Sporting Goods Stores at 5% each, Discover More CB+, Freedom, Chase Marriott, Chase Hyatt, and Diners Club Premier as the legitimate contenders for any rewards. Slate, the two BofA cards, and others are realistically not in the running for any rewards. I'm a little, though not a lot surprised by the Hyatt card taking over the various categories. I knew the Hyatt points were considered valuable, it's a good confirmation here of that. It's already in my wallet. I can't find a way to get Freedom to win out over Discover, a minor point.
The second setup adds two travel cards that are on my radar, US Bank Club Carlson, (the better of the two Carlson versions), and Citi Prestige. The Club Carlson I figured the points were worth more, just by the volume you get for regular spend. It is a good confirmation that the Prestige takes over Airlines and Hotels spend.
The third setup keeps Club Carlson and Prestige, and then adds in Citi Double Cash, also on my list of future upgrades later this year. Since Cash+ is straight up 2%, no waiting for statement payment, I can tweak that one to take over which ever category the 2% gets, gas, groceries, (not restaurants this quarter), in the Wallaby app.
The other feature of Wallaby, it puts a score on each card, so you can see how much marginally better, and the ranking, of several cards in each spend category. So in the Gas Stations category, currently Hyatt gets a score of 93, and Quicksilver is scored 91. Diners Club Premier gets only 65 points, so I think the scoring does not factor in the transfer to Alaska Miles, which other sites have scored the DC Premier at 2 cents per point. If you then add the Club Carlson to the wallet, the gas stations changes: Carlson gets a score of 87 for gas, Hyatt goes to a score of 74, Quicksilver scores 67, and DC Premier scores 61, so it's a dynamic comparison depending on the cards available. I can add any cards to my "wallet" and see how they relate, because it is optional to connect any card to your bank, no validation necessary that you actually have the card.
(Discover scores 97 in Restaurants, Freedom scores 94 for this quarter. Not sure who would take over after the Q2 anomally)
[for those looking for a gardening activity... this is an endless opportunity to dream... 
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in Airlines, Citi Prestige gets a score of 82, Hyatt gets a score of 80, not so far off.
Hotels: Prestige 90, Club Carlson 87, Hyatt 74.
Nice idea... never looked at it for evaluation purpose. Wonder if there is a limit for cards that can be added .. if not it could be endless playing around 
Did you look if the results match redemption values as well or only on the earning side ?
That's pretty cool. I've been playing with the WalletUp app (by creditcards.com, powered by wallaby) that will apparently tell you based on location services which is the better card to use while actually out and about spending and will track rewards earned and missed and your utilization ratio.
I may have to check out the card comparison tool on the other app to play around with too.
@lg8302ch wrote:Nice idea... never looked at it for evaluation purpose. Wonder if there is a limit for cards that can be added .. if not it could be endless playing around
I think this app may be weak on the "earnings possibilities" side. That's why I was surprised that Diners Club Premier does not get credit for transfers to Alaska MileagePlan, where other travel sites show Diners points worth 2 cents, which should at least raise the ranking, but in this app, Diners is treated like a 1 cent card.
Also, the possible (easy) redemption of TY Points for 1.6 when using Prestige, would seem to raise the Prestige card above Capital One Quicksilver, and yet, no joy.
Adding Sallie Mae, of course takes over Groceries and Gas, adding AMEX BCP takes over groceries, even though technically SM has a better rewards rate on groceries because no AF.
There is a feedback mechanism where you are supposed to be able to dispute the values given to a card. Haven't tried that just yet, but will be sending some notes for their algo input to chew on.
@Anonymous wrote:That's pretty cool. I've been playing with the WalletUp app (by creditcards.com, powered by wallaby) that will apparently tell you based on location services which is the better card to use while actually out and about spending and will track rewards earned and missed and your utilization ratio.
I may have to check out the card comparison tool on the other app to play around with too.
Yes, I saw this one too, it appears if you link your CC bank to get recent transactions. If you press the Rewards graphic, it lists the transactions at the bank, but does not call out (or I haven't found how) the transactions where it thinks you missed the "best" reward. That feature, feedback about card choices, would be interesting to post mortem those big value $2 coffee charges to max the rewards 
@NRB525 wrote:
@lg8302ch wrote:Nice idea... never looked at it for evaluation purpose. Wonder if there is a limit for cards that can be added .. if not it could be endless playing around
I think this app may be weak on the "earnings possibilities" side. That's why I was surprised that Diners Club Premier does not get credit for transfers to Alaska MileagePlan, where other travel sites show Diners points worth 2 cents, which should at least raise the ranking, but in this app, Diners is treated like a 1 cent card.
Also, the possible (easy) redemption of TY Points for 1.6 when using Prestige, would seem to raise the Prestige card above Capital One Quicksilver, and yet, no joy.
Adding Sallie Mae, of course takes over Groceries and Gas, adding AMEX BCP takes over groceries, even though technically SM has a better rewards rate on groceries because no AF.
There is a feedback mechanism where you are supposed to be able to dispute the values given to a card. Haven't tried that just yet, but will be sending some notes for their algo input to chew on.
I've looked at this and I'm not sure on what it bases it determination of the 'best' card. For almost every category listed other than restaurants (Freedom) it lists my NFCU Flagship card even when more points are earned with other cards. I can't imagine that the points for NFCU are more valuable than say Chase or Amex points
If you go to the category detail, what is the relative ranking, and difference in scores, NFCU vs others?