Good but- – Speedometer 55 Pro. GPS kit. Review

Been using free app- decided to buy Pro. Compass doesn’t work on old iPhone 5s, does work on iPhone 7 plus. I use iPhone 5s in motorcycles where I would want to use compass. Cannot change color of speedometer digits in full screen? Why? Is there no 0-60 mph timer? No 1/4 mile timer? Seems for a pay app there should be, maybe I just cannot find it.
Review by BWX232 on Speedometer 55 Pro. GPS kit..