Possibly, depends on the duration and severity of the flicker. Generally, a poor neutral will cause the voltage on one leg to decrease when a load is applied to that leg. The other leg will increase about the same amount. You should be able to observe this if you turn on a toaster or hair-dryer. The lights will dim or brighten depending if they are on the same or opposite leg respectively.
IoTaWatt can record average voltage in 5 second intervals. So if the voltage dips (or spikes) are significant, they will effect the average enough to be seen. You can monitor up to three voltages with a standard unit. If you monitor the two legs and one shows unusual increase when the other shows a like decrease, that’s an indicator the neutral is loose or has high-resistance.
A low tech experiment might be to place two equal wattage incandescent bulbs side-by-each and
Plug them into opposite legs. If they flicker up and down the same, it’s probably not the neutral. If one gets brighter while the other gets dimmer, suspect the neutral.