There are lots of different apps that help to identify plants, some FREE, some not.

Plant Snap is FREE and works using your phones camera (as all these apps do), and its just like taking a photo.
Our tip - zoom into the plant, otherwise the app can get confused, but we found it to be fairly accurate and very easy to use. Link to the download

Google Lens is another option - FREE of course, and it will attempt to recognised just about anything. 
If you point it at a tree it does have a tendancy to tell you about other 3 bedroom houses for sale in the neighbourhood - because it sees the house behind.
Fun though. Link to the download.