Cash App and Venmo work like checking accounts. But be wary.

Some people collect coins or stamps. For a time, I collected debit cards. Not stolen ones! Each one of them had my name on them, right below the logo of the latest banking app I’d decided to try out: Venmo, Cash App, Chime, Varo, Current, Acorns.

For the better part of a decade, I did all my…