Tic-Stack-Toe

A strategic board game of skill and memory.

Use cunning and guile to get four of your pieces in a row- horizontally, vertically, or diagonally- while preventing your opponent from doing the same.
Although similar to Tic-Tac-Toe, the fact that the pieces can stack, and thus block or hide existing pieces on the board gives added complexity to the otherwise simple sounding game.

Play against a friend on the same device.
Play against four different levels of AI.
Play against friends via Google Play Game Services.

You can also play a Junior version on a 3x3 board, and a "strict" version where there is no peeking- once you touch a piece on the board you must move it.

Additionally, you can play the game using the ELO ranking system against the AIs and friends, keeping track of your ability via a rank for each of the three game types (Junior, Normal, Strict).

The only in-app purchase is to upgrade from free/ad-based to the no-ads.

Permissions used:
*) android.permission.VIBRATE
For user feedback
*) android.permission.INTERNET
For
1) ad delivery if premium in-app upgrade not purchased
2) using achievements, leaderboards, and multiplayer games- optional
3) for AI rank update/access- optional
*) android.permission.GET_ACCOUNTS
For optional Google Play game access
*) android.permission.ACCESS_NETWORK_STATE
For optional Google Play game access
*) android.permission.WRITE_EXTERNAL_STORAGE
For storing local games' states
*) com.android.vending.BILLING
For upgrading the app to premium to remove ads