Anything you can read in the grid that is not in the list is not a word.
Every other word search fills the empty squares with random letters. Chance writes real words there; you find one, you tap it, and the app refuses without a word of explanation. Scrutix checks its filling square by square against a full dictionary, so nothing readable hides in the grid that is not on your list.
The rest follows from who it is for. Large letters, contrast checked by calculation rather than by eye, and an interface that follows your system font size all the way up to 200 %. No timer, no score, no lives, no streak to keep up: a grid is finished when every word is found, and that is the only ending there is.
Key features
No ghost words
The filling is checked against a full dictionary. What you can read, you can take.
Follows your font size, to 200 %
Most apps stop at 130 %. This one is built to hold at twice the size.
Colour and pattern, never colour alone
Two words that cross stay apart, including for colour blind players. Nothing to switch on.
Drag, or just two taps
No long press, no double tap, nothing timed. Your finger does not have to be precise.
Nothing to lose
No timer, no score, no lives. A wrong selection fades away without a sound or a penalty.
Offline, in most major languages
The hidden words and the app are set separately: look for Spanish words with a French interface.