The only app I use is iNaturalist. If I see an insect or pest that I don’t know I ID it there. it helps when you have beetles eating your plants (cucumber beetles and flower scarabs for me) or squash borers tearing up my squash. Takes time to know what is beneficial or not. Also I have learned from a couple seasons that (at least for me) specific pests only last a certain period of time and usually after a couple of weeks nature takes over. I guess the migrating birds eat the beetles for me. I don’t treat them or interfere as it has never gotten bad enough. I squish some scarabs and bought cucumber beetle traps but by the time it was delievered their numbers naturally reduced