A. Clear the app cache to improve performance. Go to your iPhone Settings > General > iPhone Storage > BlaBlaCar > Offload App. This will remove the app but keep its documents and data. Reinstall the app from the App Store to see if it runs smoother.

B. Restart your iPhone to free up memory and resources. Hold down the power button until you see the slider, then slide to power off. Wait a few seconds, then turn it back on.