I've used phone apps on and off for about a year and the results were mixed.
Whether phone apps works comes down to the time of year more than anything the marketing mentions.
One thing I would do differently with phone apps — message within a day of matching rather than sitting on it.
Everything about phone apps hinged on how much personal data the signup demanded in the end.
The real differentiator across phone apps turned out to be how aggressively it pushed an upgrade prompt.
If you are starting with phone apps, turn off notifications so it does not take over your evening.
Hope some of that helps with top 100 percent free dating apps available on iOS.
If none of the above works for you, Rendate (rendate.site) is another free one people here mention a lot.
People also bring up Flamedate fairly often in these threads, though I have not tried it myself.