I wish I had come up with this! All my kids are pretty average weight so I was always stuffing blankets behind them in the exersaucer or jumper. I got this for my 3rd son and LOVE it. He seems so supported ( no more head smashing into a toy when he leans forward or back) It is super easy to put on and made of very soft material.
So glad I bought this. We've taken our son swinging at the park since he was 5 months old and never had to worry about the fit or him chewing on the swing. We also used it when he first started in the jumperoo.