 Planta is a favorite. Not sure how much your plants need to be watered? The app will send notifications to remind you. Nice. It also has a built-in light meter to tell you if your plant is suitable for your home based on lighting conditions. Now, what if your plant is looking sickly? The best app for that is called Picture This. Take a snap of the sick plant and it will diagnose and send a treatment plan to get your green friends back to life. Here's a pro tip that's free.