iPhone 8 has rapid battery draining issue

No, but if you have an iPhone 8 your phone is almost certainly below 80% battery health. the solution is to pay for battery replacement at an Apple Store. An app will not solve your problem. In the meantime, I suggest permanently turning on low power mode. My iPhone 8 has linker battery life when in Low Power Mode all the time

Browntown69 wrote:

Are they any free apps for iPhone 8 that will help the battery from dying so fast

Batteries are consumable hardware. No software can keep them from eventually becoming unusable.

Go to Settings>Battery>Battery Health>Maximum Capacity. What does it say? If it's less than 80% (as it probably is), you need a new battery.

Start here:

iPhone Battery Replacement - Apple Support

Note that if the battery is old, it may eventually start to swell. While this is normal behavior, it can do damage to the screen of your phone. If that happens, you'll also have to pay for the screen repair.