Until now, Picsee browser extension have not been on official app stores, so this article uses Edge as an example to introduce how to install it manually...
Click this package PicseeBrowserExt-1.0.3 to download zip file, after download, unzip it.
Open Edge, click Setting and more, which is on the top-right menu bar, then look for Extensions in the contextual menu and click it.
On the bottom-left corner of the page opened, look for Developer mode, enable.
click Load unpacked
On the opened dialog, locate the folder which download and unzip before, then click select, finish to install.
After install, you will see Picsee logo on the top-right corner of Edge. Refresh the opened webpage or reopen them, drag the images in the webpages to collect.