Unfortunately it is becoming increasingly difficult to include exciting new features and improve the performance of FulGaz, while still supporting older devices and previous iOS software versions.
Many older Apple iPads and iPhones will struggle to run the latest version of FulGaz smoothly.
You may be able to improve the performance by updating to the very latest iOS software. The current version of iOS software is version 14 so if your device is on iOS 13 or below, it is several important software updates behind.
Installing the very latest iOS version might help your device to run FulGaz with more stability, but many older devices will simply struggle due to their lower processing power.