A math game "Cryptarithms" (rossposting)

Original post is here.

Would you like to play mathematics?

We developed an application to allow you such a game. The only abilities required by "Cryptarithms" are to sum numbers and perform logical reasoning.

This kind of puzzles has become popular in the first half of XX-th century in Europe. Solving the cryptarithm "send+more=money" was an intellectual challenge thrown by english mathematician Henry Ernest Dudeney. As well as today.

"Mathematical Etudes" provides an application for iPad to encourage you to meet the challenge in any of 6 languages. Solve them all.