Likely billable rate of $100-$150 at 2000 hrs per yr. Earlier on during the iOS dev crunch of 2010-2012 billable rates were hitting the $200+ mark. From 2013-2016 those rates dropped down to $150, in the past 4 years those rates plummetted to $80 and now lately even $40. Unless you're working on extending some native API or have expertise in the newer ARKits and HealthKits or you're adding value elsewhere in terms of PM or design or marketing it's harder to justify the magical $100 rate.