
As this is a huge task to review all those hundreds of programs, I invite you to join me in this effort.

Here I start.
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Today's program : Chess Tiger, by Christophe Théron (4.99 €, iPhone)
It was a surprise to see Chess Tiger make a come back... in the AppsTore, today. Amongst the hundreds of chess programs, Chess Tiger now joins a yet good bunch of classic programs: Fritz, Hiarcs, Chess Genius, Shredder, Stockfish... But how will it compare with them and justify its quite high price (4.99€)?
Interface:
Chess Tiger has a classic, sober and efficient interface. Not much candy, apart for a nice "paper corner rolling" animation when you click on a menu.

You can actually choose different board layouts and sets of chessmen:
- 12 "visual themes"
- 7 "piece sets"
- 13 "board types"
- 4 "backgrounds"
This is just the broadest possibility of choices amongst ALL the programs in the AppStore, and if I'm not mistaken that makes for 4368 possible combinations of style: you will certainly find one that fits your tastes!

The bad news is that the application is not universal, so the fonts will look pixelized on the iPad (but not the chessmen, as the graphics are antialiazed on the iPad).
Here are four examples amongst those 4368 possibilities:

Functionalities:
This program will only play the classic chess game: no variants, no chess960. But it comes with many different levels and game modes.
You can chose the strength of the engine between 28 different levels, ranging from 100 Elo ("plays at random") to 2100 Elo ("Expert, candidate master"). The program comes with two scales of strength that you can set in the preferences: USCF or Elo. But you can also unleash its full strength by setting a "game in x min" or "game in x sec" mode.
Chess Tiger comes with 7 different game modes, ranging from "Tiger doesn't play" to "Me vs Tiger", with many interesting analyzing modes in-between: this is probably the best program in the AppStore to help you analyze a game.

While playing, you can chose to let the program display a lot of tactical informations on the board (interesting if you're a beginner) :

Or go for a simpler display:

You can edit positions. During the game, you can ask the game for tips, you can go back or change sides. The engine is multi-PV and displays up to 4 pv while you play, which, again, is great in analyze mode. I don't remember there's another program doing that in the AppStore.
The program isn't meant to manage huge games databases, but it can save games and import/export them through emails and the clipboard, and it maintains a "game collection", which is yet something. You can change the name of the pgn file in the "game information" saving menu, hence using several of them. This could be made simpler but at least it exists.
Strength:
Chess Tiger is strong. VERY strong. I can't say if it's stronger than Hiarcs or Stockfish, as they all tear me to pieces, but it's Chess Tiger all right! And it's also a true tactical monster even on the small iPhone/iPad, considering its high nps for this handled platform: often over 600 knps!
You can also set the playing style in the settings, but don't expect a cool non-stress game, as these settings go from "normal" to "suicidal", with "aggressive and "very aggressive" in-between.

The opening book is quite a mammoth of a book, as it includes more than a million moves. You can chose to turn it off in the settings.
Summary and score:
Plus sides:
[*] STRONG!
[*] wide variety of graphical settings
[*] many predefined strength level, easy to understand
[*] interesting informations for the beginner
[*] many game modes (perfect for analyzing!)
[*] good import/export functionalities (could be improved though)
Minus sides:
[*] not a universal app (doesn't look so good on an iPad)
[*] the price! 4.99€ is a lot on the AppStore!
[*] the program is not localized: english only.
ReviewScore: 8.5/10
Conclusion:
The best program in the AppStore to analyse games and train your chess. Clearly Christophe designed this program as a teacher and a partner to the club player, despite it' still can be a killing machine, and it does a great job for both. Could be a bit cheaper though.