this is an area I have spent much time with not much luck. It all depends what you are looking for, what you want to pay and how smooth you want it to look. Start with these and see where that takes you. Gardroid, Garden Manager, and a cool one for identifying plants called like that garden. There is also an app called igardenusa but its $4.99. A new company called Edyn (Link) that I'm am beginning to show interest in. its a app that also has sensors for the garden bed and watering source. you can see the needs of your plants and how to help them grow to their potential. I have yet to experiment with this product myself, but I will keep you posted. the system retails for something like $99 so maybe a good Christmas present or a Great investment.

I like the idea of a garden app that helps with design, reminds of maintenance and suggests plants as well as planting time, but I think finding one that adequately does all this is a long time coming. There are just so many variables that can change garden suggestions or maintenance for any one app to be of use for everyone. I think UF learned this when they launched their own garden app. The concept of their app was great, but I think the reality of building location-specific database turned out to be too large of a job as they haven't updated the app since it was released (I think, I will have to double check to make sure.) Apps like the ones from Burpee or MG are often generalized for Temperate gardening, which describes most of the US. But for subtropic gardening, the information seemed lacking or, in some cases, wrong.

Tended App is free: https://www.tendedapp.com It lets you visually design a garden (including across different seasons, so you could keep track for crop rotation purposes), track your inputs and outputs, and see reports about your growing. There's also a calendar view with basic task management, the ability to upload photos, and it lets you see other gardeners' layouts. Check it out!