Serato DJ for iOS has a Quantize function which can be toggled by tapping the cog icon and then the “Quantize” button.

When Quantize is enabled, Cue points will snap to your Beatgrids, as you set them.

Triggering Cue points & Reloop will also snap to your Beatgrids, so that you will never go out of time while performing.

You can select the Quantize step value that the functions above snap to by tapping the cog icon in the top right corner, Advanced Settings > DJ Preferences.

NOTE: Quantize requires Beatgrids to be set.