Pocket was founded in 2007 by Nate Weiner to help people save interesting articles, videos and more from the web for later enjoyment. Once saved to Pocket, the list of content is visible on any device — phone, tablet or computer. It can be viewed while waiting in line, on the couch, during commutes or travel — even offline.
I'm in no way related nor affiliated to pocket or Mozilla, only an independant developer trying to bring something useful to the community.
I'm glad that you appreciate the addon, as it takes me a lot of my free time to develop it, fix bugs, answer support requests, well, everything you have to do when you work on this kind of projects! If you love it and want to help:
I thank you guys so much for your support and hope In My Pocket will keep on being useful to all of us!
By default, Firefox ships with its own Pocket integration (Pocket has recently been acquired by Mozilla, the foundation behind Firefox), that also provides a button in the address bar.
If you're confused with this and use a Firefox version >= 57, you can simply right-click the button and select "Don't show in the address bar". Note: when right-clicked, the In My Pocket button will show "Don't show in address bar" and "Manage extension", whereas the built-in button will only show "Remove from address bar".
You can also use this tip from the Mozilla knowledge base to disable the Pocket integration: Disable or re-enable Pocket for Firefox | Firefox help. This will make the default integration button disappear from your address bar.