What does Tymit mean by '3 months interest free'?

We offer our customers the ability to split their purchases into instalments and pay for them over time.  

If you choose to pay off in instalments of 3, we don’t charge any interest.  

However, we don’t automatically choose 3 instalments for you. You may prefer a longer repayment plan. The choice is yours.  

The important thing to remember is that you have to choose your own instalment plan for each purchase in the app.