I paid for Jet 2's insurance at the same time I was booking a flight for a skiing holiday with my son - just part of the things on offer such as meals, seat upgrades, car hire etc. On the last day our return flight was cancelled by Jet 2 - we queued for 3.5 hours to speak to Swiss Port (their handling agents at Geneva) only to be given a disclaimer notice advising we seek reimbursement of expenses through our insurance policy. Having forked out over £200 on hotel accommodation as no flight could be booked until the following day, I submitted my claim upon return. Having asked for six different pieces of documentation they then told advised me that flight cancellations were not covered!
This is an extremely poor service and I would strongly recommend that you insure through a third party and not Jet2. I shudder to think what would have happened if anyone in my party had been injured or been ill.