LessAccounting has both global and page-specific search depending on the page you're on in the app.
Click the magnifying glass in the top left to open the search field. If you are on the Dashboard, Reporting, or Settings pages, the search will be global and search the ENTIRE app. If you are on the Transactions, Invoices, or Contacts pages, the search will only search the section you are in.
For example, searching for a client's name on the Dashboard will return contacts, invoices, and transactions associated with that name. Searching for a client's name on the Contacts page will only return their contact.