I've used Garden Plan Pro for years and find it really helpful for planting times - it's more of a garden layout app but it bases the planting advice on data from your local weather station. The developer also has an app which is just a planting calendar (no layout) called Planting Calendar but I've not used that one personally. https://itunes.apple.com/us/developer/growing-interactive/id450770079

I'm sorry to tell you this but it is just not practical or efficient to garden electronically. Hardiness zones ONLY relate to winter cold tolerance - they have absolutely nothing to do with an appropriate time to to plant anything!! And "appropriate" planting times will depend widely on the plant(s) in question. And one also needs to factor in the precise location, current weather conditions, soil temperatures and in many cases, average last frost date. I have yet to encounter any sort of gardening app that is detailed enough to provide accurate information.

As an example, I have planted peas anywhere from the first week in April to early May, depending on the year. Some years the snow is gone by some time in March, but we have gotten 8" of snow during the last week of April. So I am more likely to base when I plant on what I see as far as what perennial plants and shrubs are blooming, etc.