It's really strange that electrum wallet isn't available on iOS though it is available for MAC OS. Also, they haven't released a better version for Android, don't know the reason for this ?
The popularity they have gained over the time they should have come up with best apps for both Android and iOS, but they lack in this.
Maybe because they don't have enough to pay to Android and ios developers? There is no incentive for the devs to develop it in these OS since they don't earn or get anything being a non-profitable wallet. You can ask the same for mycelium or bluewallet, why haven't they released a better app for desktop? Why are they just better in mobile mode despite being so popular?