[Plugin: Tweet Old Post] Strange problem with plugin not showing up???

I’ve had some issues with posts being tweeted to often. I went to change some of the options and noticed that the plug in isn’t showing up at all in my plugin admin….? I have no idea how the plugin is sending out tweets since the plugin doesn’t even show to be installed. Any idea what is going on??

https://www.ads-software.com/extend/plugins/tweet-old-post/