Google has released a standalone application of the Google Lens service, which used to be limited to the camera and photos application in smartphones until now. Users can access the Google Lens right from their smartphone's home screen or app drawer without having the hassle of going to Google Photos or Google Assistant for accessing it. However, there's one catch right now as the application seems to be limited to a few smartphones. I have checked for the app's availability in the OnePlus 6 and Nokia 7 Plus- both of them were compatible, but on the other hand, the Redmi Note 5 Pro and Zenfone Max Pro M1 didn't show up the app in the Google Play Store, and the direct link showed the app as incompatible.
That said, the functionality of the standalone app remains the same, but it's all about the convenience of activating the Lens. Google Lens offers the users to scan a text and copy, save the text easily from the real world; users can easily check out the places, objects by scanning them, and so on. Google Lens is getting better and better with every year.
At the recently concluded Google I/O 2018 event, Google announced that the Lens would be integrated to some smartphones camera app directly. Google has partnered with manufacturers such as Asus, HMD Global, OnePlus, Sony, Motorola, Xiaomi and so on. Right now, users with the Sony Xperia XZ2, XZ2 Compact can access the Lens right from the camera app itself.
Google Lens has been made available to Android 6.0 or above smartphone users with the Google Assistant and Google Photos until now. However, Google has now released a standalone app to make the process easier. You can head over to Google Play Store to download the application right now and use it, but as mentioned, the app is limited to only some smartphones right now.