Weetabix
Rice crispies are super high in iron, we just soak them for a little bit first so they’re soft :)
My daughter loves the multi grain Cheerios (NOT honey nut) they're low sugar, pretty good source of iron and a bunch of other important nutrients. Plus they're WIC friendly if that's something you have
Kendamil Baby Cereals are great if you have access to them (not sure what country you’re in)
We used the supermarket own brand smooth porridge (ready brek equivalent). Then we moved onto things like shredded wheat, Rice Krispies, cornflakes, and shreddies. I found that supermarket own brands of the above all had less sugar in. Cheerios have more sugar than any of the ones I’ve listed so we’ve steered clear. Once you start looking into sugar content of cereals it’s really surprising what has lots in and what doesn’t!
Weetabix, porridge
Oats with mashed banana. I don’t give my baby anything with added sugar yet