Melbet

Melbet is a practice app for learning how simple letter substitution works. It uses the Caesar shift, which pairs every English letter with another letter a fixed number of places away. The Alphabet page lets you set a shift from 0 to 25 and shows the complete letter mapping. Each plain letter appears above its encoded partner. On the Message page you enter your own text, choose Encode or Decode, and set a shift. Transform shows the result while spaces, line breaks, punctuation, digits and letter case stay as you typed them. The Examples page holds six worked puzzles. Each one shows its encoded text and shift, and you can reveal or hide the decoding steps. Exercises you transform can be saved on this device, then opened in full, edited or deleted after a confirmation. The app works offline, without an account. Melbet is made for educational puzzles and does not protect private information.